Patent Publication Number: US-2017359283-A1

Title: Music creation app in messaging app

Description:
This application claims the benefit of U.S. Provisional Patent Application No. 62/349,093, filed on Jun. 12, 2016, which application is incorporated herein by reference. This application is also related to and claims the benefit of the following U.S. Provisional Patent Application Nos. (all of which are incorporated herein by reference): 62/349,101, filed Jun. 12, 2016; 62/349,113, filed Jun. 12, 2016; and 62/349,091, filed Jun. 12, 2016. 
    
    
     BACKGROUND 
     The embodiments described in this disclosure relate to messaging systems such as text messaging systems on cellular telephones or other communication devices or data processing systems. 
     The use of text messaging systems began many years ago. For example, wireless cellular telephone carriers, such as Verizon or AT&amp;T, allowed text messages through the Short Message Service (SMS) for cell phones in the 1990s before smartphones were available. Typically, the amount of data transmitted has been limited by rules established by the carriers. Recently, as the use of smartphones (e.g. iPhones) and tablet computers (e.g. iPad) has increased, the text messaging systems have developed the ability to send images, such as photos or emojis. In addition, messaging systems such as iMessage from Apple Inc. of Cupertino, California have allowed users to also send and receive text and images through “public” networks which include “public” WiFi access points and the Internet (in addition to using the wireless carrier&#39;s private cellular telephone networks), and messaging systems such as iMessage can seamlessly transition between the use of public and private networks depending on the availability of, for example, WiFi access points or the compatibility of the other user&#39;s device (which may not be compatible with iMessage). 
     SUMMARY OF THE DESCRIPTION 
     One aspect of the embodiments described herein relate to a music creation application (app) that can display, in one embodiment, a user interface configured to receive inputs to create music in a view hosted by a first text messaging app on a device. In one embodiment, the music creation app can be an extension app or a plug-in of the text messaging app and can exchange music information with another music creation app on another device which includes a second text messaging app that hosts a view of the another music creation app. The first text messaging app and the second text messaging app can communicate music information between the two devices through one or more messaging servers. 
     In one embodiment, a method can include the following operations: displaying a first messaging app on a first device, the first messaging app configured to communicate text messages with other messaging apps including a second messaging app on a second device through one or more messaging servers; receiving a command to display a first music creation app within a view hosted by the first messaging app; and displaying, in response to the command, a user interface of the first music creation app within the view, wherein the user interface is configured to receive inputs to create music. In one embodiment, the first music creation app can either be a music creation plug-in for the first messaging app or a music creation extension app for the first messaging app. In one embodiment, the music can be created by one or more of: user inputs on a simulated musical instrument displayed within the view hosted by the first messaging app or by entry of musical notes on a musical score or by recording of information such as singing or playing a musical instrument, etc. In one embodiment, when the first music creation app is a music creation extension app, then the method can further include: sending, from the first music creation app to the first messaging app, through an interprocess communication, a file containing music data and an audio file and a graphic file depicting one or more music tracks; and sending, from the first messaging app to a second messaging app, the file containing music data and the audio file and the graphic file. In one embodiment, the audio file can be playable by the second messaging app without a second music creation app on the second device being used for playback. For example, the second messaging app may not have a music creation app installed as a plug-in or extension app, but the audio file can allow the second messaging app to play the music which was created by the first music creation app. 
     In one embodiment, the command to display the first music creation app is one of: (a) a user&#39;s selection of an icon in a user interface of the first messaging app; or (b) a user&#39;s selection of a message bubble containing data created by the first music creation app or the second music creation app. In one embodiment, the data sent from the first music creation app to the first messaging app includes a URL or other resource locator which provides for backward compatibility on devices which do not include a music creation app. 
     In one embodiment, the method can further include the operations of: receiving one or more of a modified track or an additional track of music from a second music creation app through the second messaging app, wherein the modified track or the additional track was created by the second music creation app based on the original music created by the first music creation app; displaying a new message bubble in a message transcript of the first messaging app, the new message bubble containing content based on the modified track or the additional track; converting into a breadcrumb a prior music message bubble containing music content identified with the same session identifier as the music content in the new music message bubble. 
     In one embodiment, the first music creation app can call, through an application programming interface, to the first messaging app to request a change of the first music creation app&#39;s view within the first messaging app, wherein the change is a switch between a compact view in which the first messaging app&#39;s message transcript is viewable, and an expanded view in which the message transcript is not viewable. In one embodiment, when the music creation app is an extension app, the first messaging app executes in a first sandboxed process and the first music creation app executes in a second sandboxed process that is distinct from the first sandboxed process. In one embodiment, the first messaging app can encrypt the music data provided by the music creation app before sending it to the second messaging app. 
     The methods and systems described herein can be implemented by data processing systems, such as one or more smartphones, tablet computers, desktop computers, laptop computers, smart watches, wearable devices, audio accessories, on-board computers, and other data processing systems and other consumer electronic devices. The methods and systems described herein can also be implemented by one or more data processing systems which execute executable computer program instructions, stored in one or more non-transitory machine readable media that cause the one or more data processing systems to perform the one or more methods described herein when the program instructions are executed. Thus, the embodiments described herein can include methods, data processing systems, and non-transitory machine readable media. 
     The above summary does not include an exhaustive list of all embodiments in this disclosure. All systems and methods can be practiced from all suitable combinations of the various aspects and embodiments summarized above, and also those disclosed in the Detailed Description below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings in which like references indicate similar elements. 
         FIG. 1A  shows an example of a user interface for a messaging app on a communication device. 
         FIG. 1B  shows another example of a user interface for a messaging app on a communication device. 
         FIG. 2  shows an example of a messaging system which employs one or more messaging servers to provide a messaging service to a set of client devices. 
         FIG. 3A  shows a block diagram of an architecture for providing extension apps for use with a messaging app according to one embodiment. 
         FIG. 3B  shows an example of a user interface of a message bubble created at least in part by an extension app according to one embodiment herein. 
         FIG. 3C  shows an example of parts of a message bubble based on a template. 
         FIG. 4A  is a flowchart which shows a method according to one embodiment for browsing, selecting, and launching an extension app from within a messaging app according to one or more embodiments described herein. 
         FIG. 4B  shows an example of a user interface for a messaging app which includes a browsable view of installed extension apps according to one embodiment described herein. 
         FIG. 5A  shows an example of a user interface of a messaging app which includes a view of an extension app within the user interface of the messaging app. 
         FIG. 5B  shows an example of a user interface of an extension app, after the user has created content in the extension app, wherein the view of the extension app is hosted within the user interface of the messaging app. 
         FIG. 5C  shows an example of a user interface of a messaging app on a communication device after the user has created content using an extension app and has sent the content by using the messaging app to send the content. 
         FIG. 5D  shows an example of a user interface in a messaging app on a receiving device after the receiving device receives content created by an extension app on the sending device. 
         FIG. 5E  shows an example of a user interface on a receiving device when the user of the receiving device selects the message bubble containing the content created by the extension app on the sending device so that the user of the receiving device can edit the content on the receiving device. 
         FIG. 5F  shows an example of a user interface which offers to download and install an extension app for use with the messaging app on the device. 
         FIG. 6  is a flowchart which illustrates a method which can be performed on a receiving device according to one embodiment described herein. 
         FIG. 7A  is a flowchart which depicts a method according to one embodiment in which an extension app can change its view hosted by a messaging app according to one embodiment. 
         FIG. 7B  shows an example of a user interface of an extension app in an expanded view according to one embodiment. 
         FIG. 8  shows an example according to one embodiment in which extension apps on two or more devices can interact with each other through the messaging apps on each device. 
         FIG. 9A  is a flowchart which illustrates a method according to one or more embodiments described herein for allowing the interaction between extension apps on different devices. 
         FIG. 9B  shows an example of a message bubble in a user interface which can result from the method shown in  FIG. 9A  when two or more extension apps interact in a session. 
         FIG. 9C  shows an example of a message bubble according to one embodiment in which a download and install for a required extension app occurs while the messaging app remains in the foreground. 
         FIGS. 9D, 9E, 9F, 9G, and 9H  show an example of the message transcripts on two different devices that are involved in a conversation between two messaging apps, one on each device, wherein the conversation involves a session between two extension apps. The user interface shown in  FIGS. 9D, 9E, 9F, 9G and 9H  show how content in message bubbles created by the extension apps can be converted into breadcrumbs according to one or more embodiments described herein. 
         FIG. 10  is a flowchart which illustrates a method according to one embodiment described herein. 
         FIG. 11  is a flowchart which illustrates a method according to one embodiment described herein. 
         FIG. 12  shows a user interface of a messaging app in which content from two or more different extension apps is presented within the same message transcript provided by the messaging app. 
         FIG. 13A  is a flowchart which shows a method according to one embodiment for providing backward compatibility for older devices or older messaging systems. 
         FIG. 13B  shows an example of a user interface in which backward compatibility has been provided within a messaging app. 
         FIG. 14A  shows a method according to one embodiment in which a receiving device (which has received a message) downloads and installs an extension app required to view or interact with the content in one of the messages. 
         FIG. 14B  shows an example of a user interface of an extension app marketplace or service from which extension apps can be downloaded and installed. 
         FIG. 15A  is a flow chart which shows a method according to one embodiment which can be performed on a first device. 
         FIG. 15B  is a flow chart which shows a method in one embodiment which can be performed on a second device that can collaborate in the creation of music with the first device of  FIG. 15A . 
         FIGS. 16A, 16B, 16C, 16D, 16E, 16F, 16G, 16H, 16I, 16J, and 16K  show an example of the user interfaces of two different devices which are engaged in a collaborative music creation process through the use of a first music creation app on a first device and a second music creation app on the second device. 
         FIG. 17  is a block diagram illustrating an exemplary API architecture, which may be used in one or more of the embodiments described herein. 
         FIG. 18  shows a block diagram illustrating a software stack which can include one or more applications and services in operating systems. 
         FIG. 19  shows an example of a data processing system which can be used in one or more embodiments described herein. 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments and aspects will be described with reference to details discussed below, and the accompanying drawings will illustrate the various embodiments. The following description and drawings are illustrative and are not to be construed as limiting. Numerous specific details are described to provide a thorough understanding of various embodiments. However, in certain instances, well-known or conventional details are not described in order to provide a concise discussion of embodiments. 
     Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in conjunction with the embodiment can be included in at least one embodiment. The appearances of the phrase “in one embodiment” in various places in the specification do not necessarily all refer to the same embodiment. The processes depicted in the figures that follow are performed by processing logic that comprises hardware (e.g. circuitry, dedicated logic, etc.), software, or a combination of both. Although the processes are described below in terms of some sequential operations, it should be appreciated that some of the operations described may be performed in a different order. Moreover, some operations may be performed in parallel rather than sequentially. 
     The various embodiments described herein relate to messaging systems such as text messaging systems or “chat” messaging systems or other systems which allow devices to communicate messages between the devices. For example, iMessage from Apple Inc. of Cupertino, Calif. is an example of a messaging service for iOS devices and Mac (OS X) computers. Typically, a messaging system includes the plurality of client devices, each including at least one messaging app, and a set of one or more messaging servers that can receive messages from client devices and transmit messages to client devices.  FIG. 1A  shows an example of a user interface of a messaging app on a client device. The client device can be a communication device  10  which can be a smartphone, or tablet computer, or a desktop computer or a laptop computer, wearable device, on-board computer, or other data processing systems or other consumer electronics devices. In one embodiment, the device can include a conventional touch screen that can both display images and also accept touch inputs from a user. The touch screen  12  on the communication device can display the user interface of the messaging app which can include a message transcript  16  and an on-screen keyboard  20  below the message transcript  16 . In addition, the user interface of the messaging app can include a user name  14  indicating the recipient, in one embodiment, of messages sent from the communication device  10 . In addition, the user interface can include a text entry region  18  which indicates the content of the text entered by the user before it is sent; in a sense, the text entry region  18  is a text staging area indicating text that is ready to be sent to the recipient. 
       FIG. 1B  shows a more detailed example of a user interface of a messaging app on a communication device  10 A. The user interface is displayed in this embodiment on touch screen  12 A and includes on-screen keyboard  20 A, text entry region  18 A, a message transcript  16 A and a user name  14 A showing the name of the other user(s) to whom messages are sent and from whom messages are received. The text entry region  18 A is a staging area for content such as one or more of text, stickers, extension app content, images etc. which are ready to be sent in response to the user&#39;s selection of the send command (and in one embodiment, the content can be edited in the staging area). In the example shown in  FIG. 1B , messages from Freddy (user name  14 A) are shown on the left side of the message transcript  16 A and messages sent by the user of communication device  10 A are shown on the right side of message transcript  16 A. Hence, message bubble  17  shows the message “Where at?” sent by the user of communication device  10 A to Freddy as a response to the message from Freddy “Dinner tonight?”. The message in message bubble  17  causes Freddy to respond with “How&#39;s this?” shown in message bubble  19 . The use of the word “bubble”, such as message bubble or session bubble, etc. is not meant to imply any specific shape or form; rather it is intended to mean any shape or form of demarcation between messages between two or more participants, and thus the demarcation can use boxes or lines or message containers or different colors, etc. Thus the phrase “message bubble” is meant to cover all such demarcations (or other ways to distinguish) between messages between two or more participants, and particularly in the context of such demarcations or other ways to distinguish in a message transcript. In one embodiment, the message transcript can be scrolled up and down and messages in the message transcript are presented in sequence according to their time, thus the user can see the actual chat or conversation over time by scrolling the view up or down. The user interface shown in  FIG. 1B  also includes three icons  22 ,  23 , and  24  above the on-screen keyboard  20 A and to the left of the text entry region  18 A. The extension apps view icon  22 , when selected, causes the display of a view of the installed extensions app that can operate with the messaging app, and the view provided can be a browsable view, such as the browsable view  157  shown in  FIG. 4B  to allow the user to scroll through multiple pages showing all of the installed extension apps that are configured to operate with the messaging app according to the one or more embodiments described herein. The imaging app icon  23  can in one embodiment be an icon that when selected causes the launching of a plugin of the messaging app that provides image creation within the messaging app&#39;s process such as the plugin shown in  FIGS. 5A, 5B, and 5C . The camera app icon  24  in one embodiment can, when selected, cause the communication device  10 A to enter into a camera mode in which a camera of a device can capture still images or video images which can be placed into the message in order to send the image or video. 
     A brief overview of an example of a messaging system will now be provided in conjunction with  FIG. 2 . A messaging system  50  can include a plurality of client devices, such as client devices  53  and  54 . Each of these client devices can include at least one messaging app that is configured to operate with extension apps according to the one or more embodiments described herein and also communicate at least text messages and optionally resource locators or images or other content (e.g. as described relative to  FIG. 13A ) for devices that are not compatible with the extension app architecture in a messaging app. In a typical messaging system, there can be millions of client devices communicating through a set of messaging servers. In one embodiment, a plurality of messaging servers can be configured to receive encrypted messages from sending devices and then transmit those encrypted messages to the receiving devices. Another set of servers can be configured to receive non-text content, such as images or other “attachments” and provide those images or attachments in download operations to receiving devices in response to requests from those receiving devices to obtain the images or attachments. In one embodiment, a sender&#39;s outgoing message is individually encrypted for each of the receiver&#39;s devices. In one embodiment, an asymmetric RSA encryption algorithm can be used to perform the encryption. In one embodiment, the public RSA encryption keys of each of the receiving devices can be retrieved from a directory service (maintained by the one or more messaging servers) which includes a database, such as a database  52  which is coupled to the one or more messaging servers  51 . When a client device, such as client device  53  seeks to send a message to another client device, it identifies the other client device (such as by an email address or a telephone number or other identifier) to the one or more messaging servers  51 . That identifier is sent from the client device, such as client device  53  to one or more messaging servers  51  which then perform a lookup operation in the database  52  based upon the supplied identifier to retrieve the public key that corresponds to that identifier. That public key is then transmitted back to the client device which requested the public key for that particular receiving device, and then the client device can encrypt the message using the public key or using another key (e.g. a symmetric key) which can be randomly generated, and that other key is encrypted with the public RSA encryption key for the particular receiving device. In one embodiment, the randomly generated key can be randomly generated on a per message basis. In one embodiment, the resulting messages, one for each receiving device, consists of the encrypted message text, the encrypted message key, and the sender&#39;s digital signature, and this resulting message for each receiving device is then uploaded to the one or more messaging servers  51  for delivery to the recipient client devices, such as client device  54 . In one embodiment, the messaging system  50  can be configured to operate through “public” networks which include public WiFi access points (such as WiFi access points in coffee shops, airports, etc.) and also the Internet. The messaging apps on each of the client devices  53  and  54  can also be configured to operate with the “private” networks provided by wireless cellular telephone carriers, such as Verizon and AT&amp;T, and the messaging apps can be configured to seamlessly switch between the use of the private and public networks depending upon the availability of each and also depending upon the compatibility of each of the client devices in a messaging session. In one embodiment, the messaging servers  51  can include a set of push notification servers which receive the uploaded text messages and which “push” those text messages to receiving devices. 
     A messaging system in one embodiment on a client device includes a messaging app and one or more extension apps that each operate as separate processes. In one embodiment, the message app and the one or more extension apps can each be separate sandboxed processes that operate or execute in their own memory spaces. In addition, the messaging app can also operate with plug-ins, such as an image creation plug-in shown in  FIG. 5A , which operate within the same process and memory space as the messaging app. The messaging app and each extension app communicate with each other through an interprocess communication, such as the XPC framework provided in iOS and Mac OS X. The messaging app is designed to receive text on a sending device from a user of the device and display the text in a message transcript and send the text, through a set of one or more messaging servers, to a receiving device which displays, through a counterpart messaging application on the receiving device, the received text in a message transcript on the receiving device. The receiving device and the sending device can each have a copy of the same extension app which is configured to create content of a certain type depending upon the particular extension app (or, in an alternative embodiment, each can include a copy of different extension apps that are compatible for the content used by them). 
       FIG. 3A  shows an example of a software architecture in which a messaging app and one or more extension apps operate together to provide an enhanced messaging system. As shown in  FIG. 3A , the messaging system  75  includes a messaging app  76  and a set of plug-in modules, such as a composition module  77  and a data transport module  79  which are configured to communicate through an interprocess communication (IPC)  81  with the one or more extension apps  83 . As shown in  FIG. 3A , the messaging app and the composition module  77  and the data transport module  79  operate within the messaging app processes in a memory space controlled by a kernel on the communication device which executes the messaging system  75 . The composition module  77  composes the content of a message bubble when the message bubble displays or otherwise presents content passed to the messaging app through the IPC  81 . The data transport module  79  passes the content and other data to the extension app through the IPC  81  and receives the content and other data from the extension app through the IPC  81 . Both modules  77  and  79  in one embodiment can have an extendable plug-in architecture that allows the addition of new plug-ins for new extension apps that generate new content or require a new data transport process. In this context, the plug-ins are additional software that operate within the same process as the messaging app. The composition module  77  can use a template to construct a message bubble such as the “MSMessageTemplateLayout” described below relative to  FIG. 3C . The kernel can include a software library or software framework for providing the IPC  81  to allow communication between the messaging system  75  and the one or more extension apps  83 . In one embodiment, the IPC framework can include a system area that is referred to as an extension point which provides APIs to allow for communication between the two different processes and to reinforce policies in terms of the types of communications which are permissible. In one embodiment, the communication through IPC involves the placement (writing) of content in a memory region by one process and the IPC framework allows another process to read from that memory region. In one embodiment, the messaging app  76  can launch automatically the extension app processes and can manage their lifetime, including the termination of those processes. In one embodiment, each of the extension apps  83  run in their own address space, communication between the extension and the messaging app uses the IPC mediated by the system framework and they do not have access to each other&#39;s files or memory spaces. In one embodiment, each of the extension apps may be a sandboxed process which is separate from other extension apps, and the messaging app  76  can also be a separate sandboxed process which is separate from the sandboxed processes of the extension apps. Moreover, the extension apps can be provided with fewer system permissions relative to the messaging app so that the extension apps operate in a more restricted environment than the messaging app. Further information in connection with the use of interprocess communications for extensions can be found in U.S. patent application Ser. No. 14/488,122, filed Sep. 16, 2014 and published as U.S. Publication No. U.S. 2015/0347748, which application is incorporated herein by reference. 
     In one embodiment the messaging app provides a view of content obtained from the extension app through the interprocess communication. The extension app can create the content in its own process and then provide that content in formats known to be acceptable to the messaging app (such as standard image formats or other standard formats). This allows the messaging app to then present the content from the extension app within one or more message bubbles within a message transcript (without needing to execute the extension app at least on the receiving device).  FIG. 3B  shows an example of a message bubble  17 A which contains content created by and provided from an extension app, shown as content  85  which also can include a text message created by or provided by the extension app, such as text message  86 . In one embodiment, the message bubble  17 A can also include an icon  87  which can be the icon of the extension app which created the content  85 . 
     Objects created by an extension app in one embodiment are shown in the message transcript on sending and receiving devices without launching the extension app. The extension app should provide enough information to construct a message bubble as part of the object. The object can consist of some opaque data encoded in a resource locator and a layout specification provided as a MSMessageTemplateLayout object. MSMessageTemplateLayout is a subclass of MSMessageLayout and represents one method of specifying message bubble layout. 
     MSMessageTemplateLayout can have the following properties in one embodiment which are shown in  FIG. 3C : 
     1) image or mediaFileURL: An image provided as a UIImage or as a file URL to an image file or a file URL to a video 
     2) imageTitle: A string the will be rendered on top of the image or movie 
     3) imageSubTitle: A string the will be rendered on top of the image or movie below the imageTitle 
     4) caption: A string the will be rendered in a caption bar below the image or movie 
     5) trailingCaption: A string the will be rendered right aligned in a caption bar below the image or movie 
     6) subCaption: A string the will be rendered in a caption bar below the caption 
     7) trailingSubCaption: A string the will be rendered right aligned in a caption bar below the trailingCaption 
     8) Extension icon: This is not provided as part of the MSMessageTemplatcLayout but is derived from the bundle identifier of the extension that created the MSMessage. 
     The messaging app can use this information to construct the message bubble similar to the example shown in  FIG. 3C . 
     The MSMessageTemplateLayout is serialized and transferred to the remote devices along with the opaque data. On receipt the messaging app on the receiving device will create a MSMessageTemplateLayout using the serialized data and use this to draw the message bubble in the receiver&#39;s message transcript. 
     In one embodiment, the extension apps which are configured to operate with a messaging app are not executable outside of the messaging application, and thus their life cycle is managed entirely by the messaging app. Moreover, as further described below, the downloading and installing of the extension apps can be controlled exclusively by the messaging app in one embodiment. 
     In one embodiment, each extension app can be obtained from an app marketplace or distribution facility such as the Apple App Store (trademark) for message extension apps and can be launched from within the messaging app.  FIG. 4A  shows an example of a method according to one embodiment in which the installed extension apps can be browsed from within the messaging app, and a particular extension app can be launched to allow the user to interact with a particular extension app. The method can begin in operation  101  in which the messaging app displays its message transcript and an on-screen keyboard.  FIG. 1B  shows an example of a user interface of such a messaging app. Then in operation  103 , the messaging app can receive an input to display a browsable view of installed extension apps within a view of the messaging app. For example, a user may tap on the icon  22  (in  FIG. 1B ) to select the icon which in turn causes the display of the browsable view in operation  105 . In one embodiment, the browsable view of installed extension apps takes the place of the on-screen keyboard and retrieves the list of the installed extension apps from an extension registry which causes the display of icons for each of the installed extension apps.  FIG. 4B  shows an example of the result of operation  105  in which a browsable view  157  is displayed and takes the place of the on-screen keyboard of the messaging app as shown in  FIG. 4B . 
     Referring to  FIG. 4B , it can be seen that the browsable view  157  includes a plurality of icons each representing one of the installed extension apps that can operate with the messaging app that provides the user interface shown in  FIG. 4B . The user interface of the messaging app shown in  FIG. 4B  includes a message transcript  153  shown in the upper portion of the touch screen  151  on the communication device  150  which executes the messaging app. A user name  155  of the other user (recipient of messages sent from communication device  150 ) is shown at the top of the user interface of the messaging app. A text entry region  155  (which shows text or other content that is staged or ready to be sent) is displayed between the message transcript  153  and the browsable view  157 . In one embodiment, the browsable view is browsable by swiping the user&#39;s finger across the touch screen to cause the pages in the various views of installed extension apps to be displayed (and in one embodiment, can also show, for example, uninstalled extension apps that either need to complete a download process or need to complete an install process). In one embodiment, a page indicator  159  at the bottom of the user interface can show the current page of installed extension apps. In one embodiment, one of the icons can be reserved to launch or enter the extension app marketplace, an example of which is shown in  FIG. 14B . In another embodiment the extension app marketplace can be displayed in the browsable view  157  in response to selecting icon  167 . In the embodiment shown in  FIG. 4B , the icon  167  is the extension app marketplace icon which can be selected to cause the presentation of the extension app marketplace, such as the extension app marketplace shown in  FIG. 14B . In the embodiment shown in  FIG. 4B , the icon  169  can be selected (e.g. user taps icon  169 ) to cause the display in the browsable view of recently sent stickers or handwritten messages or other recently sent items or recently used apps, etc. The display of recently sent items, etc. can in one embodiment be provided by a plug-in operating within the messaging app&#39;s process. Other extension apps include a restaurant reservation app icon  161  which can be an extension app that can be used to engage a restaurant reservation service, such as Open Table. Another example of an extension app is represented by icon  163  which when selected launches a restaurant review app which provides reviews of restaurants and which can be similar to the reviews provided by Yelp, for example. The other extension app icons  165  and  171  represent other extension apps which are installed and which can be launched by selecting one of those extension app icons. 
     Referring back to  FIG. 4A , once the browsable view is displayed by operation  105 , the user can select one of the extension apps by selecting the corresponding icon which in turn causes the launching of the selected extension app in operation  107 . In one embodiment, the messaging app calls a system service to launch the selected extension app and prepare it for execution as an extension of the messaging app using the architecture shown, for example, in  FIG. 3A . Once the selected extension app has been launched and is executing, the messaging app, such as messaging app  76  can host the view of the content provided by the executing extension app through the IPC framework as described herein. For example, in operation  109  shown in  FIG. 4A , the messaging app can display a view of the content provided by the extension app within a portion of the view of the messaging app.  FIGS. 5A through 5F  will now be described as examples of how the messaging app hosts the view of the content of the executing extension app. 
       FIG. 5A  shows an example of a messaging app that hosts a view of a plug-in of a messaging app that is an image creation app launched by selecting the icon  207  (e.g. icon  207  is touched or tapped or otherwise selected by a user). In another embodiment, the plug-in shown in the bottom portion of the user interface shown in  FIG. 5A  may be launched by selecting one of the icons in the browsable view  157  shown in  FIG. 4B . While the example shown in  FIG. 5A  can be implemented as a plug-in of the messaging app, in another embodiment, the example shown in  FIG. 5A  can be an extension app. In the example shown in  FIG. 5A , the view of the plug-in (or extension app) has taken the place of the on-screen keyboard of the messaging app, but the message transcript of the messaging app is still viewable and displayed in the user interface, allowing the user to scroll through the message transcript in one embodiment to see the entire transcript. In another embodiment, the view of the plug-in or extension app is an overlay on top of the on-screen keyboard, a portion of which may be viewable. The transcript is displayed on the touchscreen  202  in one embodiment on the communication device  200 . The user interface of the messaging app also includes the user name  203  which presents in one embodiment the name of the other user in the conversation or chat. The user interface of the messaging app also includes the text entry region  211  which is similar to the text entry region  18 A and the text entry region  155 . The plug-in (or extension app) includes a drawing canvas  215  and various controls and options which can be selected by the user to draw or create images. Drawing controls  212  in one embodiment can allow the users to select different colors to sketch on the drawing canvas if the sketch option  217  is selected. The plug-in (or extension app) can also provide taps as a message if the tap option  221  is selected. The plug-in (or extension app) can also provide heartbeats if the heartbeat option  219  is selected. In one embodiment, the sketch, heartbeat, and taps can be similar to the sketch, heartbeat and taps on the Digital Touch application which is available on the Apple Watch. The plug-in (or extension app) also includes an expanded view icon  223  which when selected can cause the plug-in (or extension app) to switch from its current compact view shown in  FIG. 5A  to an expanded view, such as the expanded view shown in  FIG. 7B . In the example shown in  FIG. 5A , the user has just launched the plug-in image creation app (or an extension app in the alternative embodiment) and has not yet created any content. This can be contrasted with the state of the plug-in (or extension app) shown in Figure SB in which the user has created a happy face sketch by using the sketch option  217  and by drawing on the drawing canvas  215  with, for example, the user&#39;s finger. The user can then cause the drawing to be sent to the other user (or users) who would be recipients for the message. Thus for example, the user of the device  200  can select a send command from within the messaging app executing on communication device  200  to cause the content created by the plug-in (or extension app) to be sent to the recipients. The result of the sending operation is shown in  FIG. 5C  in which the happy face has been sent to Freddy as indicated by the user name  203 . The message bubble  230  shows the happy face sketch that was created by the plug-in (or extension app); in the case of the extension app, this created content was communicated from the extension app through the IPC framework to the messaging app and then presented within the message bubble  230  to show that the message containing that content was transmitted to one or more recipients. In one embodiment, a delivery indicator  231  can indicate that the message was delivered and a keep control  232  can be provided to the user to allow the user to retain the content in the message transcript in those embodiments in which the content can be automatically eliminated after a period of time. 
       FIGS. 5D, 5E, and 5F  illustrate what can happen on the receiver&#39;s device in response to receiving the content from the communication device  200  shown in  FIG. 5C . Also, the flowchart shown in  FIG. 6  can show the method performed at the receiving device, such as the communication device  250  shown in  FIGS. 5D, 5E, and 5F . Referring now to  FIG. 5D , it can be seen that the communication device  250  (used by Freddy) has received the happy face content which is shown in message bubble  253 . This content was created by the extension app executing on communication device  200  which provided the happy face content to the messaging app executing on communication device  200  which in turn transmitted that content through a messaging service (e.g., a set of messaging servers, such as the messaging servers  51  shown in  FIG. 2 ) to the messaging app executing on the communication device  250  which in turn presented the content in the message bubble  253 . In one embodiment, the content can be rendered by the messaging app as it uses known standard formats (including standard image, audio, and video formats in one embodiment) and thus the extension app need not be installed or executing in order to show the content created by the counterpart (remote) extension app on the sending device. Thus in this case as shown in  FIG. 5D , the message bubble  253  can present the content even though the counterpart extension app may not be executed or may not even be installed on the communication device  250 . The messaging app shown in  FIG. 5D  includes, in its user interface, a message transcript  201 A, a text entry region  211 , and an on-screen keyboard  255 . In one embodiment, content received from a remote extension app will not cause the launching automatically of the corresponding extension app on the receiving device even if the corresponding extension app is installed. In this embodiment, the corresponding extension app on the receiving device can be launched by the user&#39;s selection of the message bubble containing the content created by the remote extension app. If the user does select that content by, for example, touching or otherwise selecting the message bubble  253 , then the extension app that corresponds to the remote extension app will be launched if installed on the communication device  250 . The result is shown in  FIG. 5E  in which the user interface of the extension app has occupied the space in which the on-screen keyboard  255  was previously displayed and shows the happy face drawing within the canvas  215  allowing the user of the communication device  250  to alter or otherwise modify that sketch and perhaps send it back to the other user in the chat session or conversation. If, on the other hand, the corresponding extension app is not installed on the communication device, then in one embodiment the messaging app can present a notice to the user asking or offering to install the app for the particular message bubble which was selected. An example of this is shown in  FIG. 5F  in which the notice  259  includes two user selectable options, one of which will install the required app for the message bubble. In another embodiment, a sheet that shows a page of information from an extension app marketplace can be displayed within the view of the messaging app. 
     In one embodiment, the message transmitted from the remote device to the communication device  250  contains metadata which specifies the remote extension app used to create the content. In one embodiment, this metadata can be an app identifier, such as an identifier provided by an app marketplace or an extension app marketplace from which the extension apps can be downloaded and installed or can be a different identifier that can be associated with the identifier used by the app marketplace. In one embodiment, the notice  259  can result from the selection of the message bubble  253 , while in another embodiment it can result automatically if the app identifier in the metadata for the content is not installed when the content for the message bubble  253  is received by the communication device  250 . 
       FIG. 6  will now be referred to in conjunction with  FIGS. 5D, 5E, and 5F  to explain a method in one embodiment in which a receiving device processes content created by a remote extension app, such as the remote extension app executing in conjunction with the messaging app on communication device  200 . In operation  301 , a communication device can receive a message with content created by an extension app, such as a remote extension app operating in conjunction with a messaging app on a sending device. In addition, the communication device can also receive the metadata which can include a message bubble identifier, session identifier and an extension app identifier and potentially other data such as an optional resource locator and other data (state information) that may be associated with the optional resource locator and the resource locator may also include state information that is encoded into the resource locator. Further information with respect to the use of resource locators and data associated with the resource locators will be provided in conjunction with  FIGS. 8, 9A, and 9B . Then in operation  303 , the communication device which has received the message in operation  301  processes the content and displays the content in a message bubble which was identified by the message bubble identifier, and the message bubble is displayed within the message transcript. In one embodiment the processing of the content can include decrypting the content and rendering the content for presentation and display within the message bubble. In one embodiment, the content is displayed by the messaging app without assistance from the extension app; in other words, the extension app may not be installed or if installed is not executing on the communication device, and hence the on-screen keyboard is displayed in one embodiment. Then in operation  305  the communication device receives a selection of the message bubble displaying the content created by the remote extension app. In one embodiment, referring to  FIG. 5D , the user can tap on the message bubble on a touchscreen or otherwise select (e.g. user uses a stylus on a touchscreen or uses a mouse with a desktop computer, etc.) the message bubble  253  to cause the selection in operation  305 . In response to operation  305 , the communication device, such as communication device  250  determines in operation  307  whether or not the extension app is installed. This can be performed in one embodiment by examining a list or registration of installed extension apps maintained by the messaging app. In one embodiment, the metadata received in operation  301  includes the app identifier, and the messaging app in operation  307  searches the list to determine whether the identifier is present in the list. If the identifier is not present in the list then the messaging app determines that the extension app is not installed, thereby causing the communication device to perform operation  309  in which the notice  259 , shown in  FIG. 5F , can be displayed to the user to offer to download and install the app specified by the app identifier which was received as part of the metadata in operation  301 . If the user selects the option “yes” then operation  311  is performed in which the messaging app causes the communication device to access the extension app marketplace (such as the extension app marketplace having a user interface shown in  FIG. 14B ) to retrieve through a download process a copy of the extension app and to cause the extension app to be installed. In one embodiment, operation  311  may be performed entirely in the background so that the messaging app remains the foreground app during the download and install process.  FIG. 9C  shows an example of a message bubble  471  maintained in a message transcript during the download and install process, where the message bubble includes a progress bar  473  which indicates the progress of the download and install operation while the messaging app remains the foreground application displaying the message bubble  471  in the message transcript of the messaging app. In another embodiment of the operation  311 , a sheet that shows a page of information from an extension app marketplace can be displayed over the messaging app (with a portion of the messaging app optionally still displayed), and the sheet can show a “buy” or install or download button, which if selected, can cause the download and installation of the extension app, and the sheet can be dismissed (removed from display) either by selecting a dismiss command or by selecting buy or install or download. After downloading and installing the extension app, processing can proceed to operation  313  in  FIG. 6  in which the extension app is launched and the content and other data used or created by the remote extension app is passed (via IPC) to the extension app by the messaging app, and the extension app is displayed in either a compact or expanded view in one embodiment and the content created by the remote extension app is displayed within that view. As shown in  FIG. 6 , operation  313  also follows operation  307  if operation  307  determines that the extension app is installed.  FIG. 5E  shows one example of the result of operation  313 . 
     In one embodiment, a messaging app can launch different types of extension apps in different ways depending upon the type of the extension app. For example, one type of extension app can be launched automatically in response to receipt of a message bubble containing content from an extension app having a certain predetermined type. Other extension apps having a different type may only be launched in one embodiment in response to the selection of a message bubble containing content from that extension app or by the selection of an icon representing the extension app in a browsable view, such as browsable view  571 . It may be desirable to allow certain extension apps having a certain type to be launched automatically in response to receiving content that is displayed within the message transcript while not automatically launching other types of extension apps. In another alternative embodiment, one or more extension apps can be permitted to execute in the background and can be allowed to update their respective user interfaces that are presented in their respective message bubbles. 
     In an alternative embodiment, the metadata can include a format or extension identifier such as an identifier of an image format that can be used to determine available extension apps that can process that image format on the receiving device. 
       FIGS. 7A and 7B  illustrate another aspect of the embodiments described herein in which the extension app can cause a view to be changed by sending communications to the messaging app to cause that change. In one embodiment, an application programming interface (API) can be provided between the extension app and the messaging app to allow the extension app to make calls to that API to change its view within the messaging app which hosts the view of the extension app. In one embodiment, an extension app can have at least two different views which can include a compact view and an expanded view. In one embodiment, the compact view may be a view which takes the place of the on-screen keyboard of the messaging app while the message transcript remains displayed in the user interface of the messaging app. In the expanded view, the message transcript is no longer displayed and the on-screen keyboard is not displayed but certain other components of the user interface of the messaging app, such as text entry region  211  and a camera activation icon  235  are displayed.  FIG. 7B  shows an example of an expanded view in which the drawing canvas  215 A occupies most of the space of the touch screen. As shown in  FIG. 7B , the compact view icon  223 A can be selected by the user to cause the system to change from the expanded view shown in  FIG. 7B  back to the compact view, such as the view shown in  FIG. 5A . 
     The method shown in  FIG. 7A  is one embodiment showing how the view can change, and it will be appreciated that in alternative embodiments, the sequence of operations may be performed in a different order and there may be omitted steps or intervening steps or additional steps. 
     In operation  351  of  FIG. 7A , the extension app is displayed by the messaging app with a particular view or style. In operation  353 , the extension app can make a call to the messaging app to get the current presentation view/style of the extension app. In operation  357 , the messaging app can provide a return for the call from operation  353 , and that return can indicate the current presentation view/style of the extension app. In response to that current presentation received in operation  357 , the extension app can request a change in the presentation view/style by providing a call to the messaging app to cause that change to occur, and that call is received in operation  361 . The messaging app in one embodiment can initially respond to this call with an acknowledgement that the view is being changed or will be changed. In response to the call, in operation  363 , the messaging app changes the presentation style/view and displays the extension app within the requested view presentation view/style and in operation  365  the messaging app informs the extension app that the change of view has been completed. Referring back to  FIG. 7B , if the user selects the compact view icon  223 A, this can cause a call from the extension app to the messaging app to change the view of the extension app within the user interface of the messaging app. 
       FIGS. 8, 9A, 9B, and 9C  will now be described relative to another aspect of the embodiments presented herein. In one aspect of this embodiment, an extension app and a counterpart extension app on another device can engage in a communication session and exchange information back and forth in their communication session, and all of this occurs within the context of a message transcript maintained by the two messaging apps which interface between the two extension apps as shown in  FIG. 8 . In one embodiment, plug-ins for a messaging app can also operate in a similar way and exchange information between the plug-ins through two messaging apps that are in a session. The messaging system  400  shown in  FIG. 8  includes at least two clients devices, client device  401  and client device  405  and also includes a set of one or more messaging servers  403 . The client devices  401  and  405  can be similar to the client devices  53  and  54  in  FIG. 2 , and the set of one or more messaging servers  403  can be similar to the set of messaging servers  51  shown in  FIG. 2 . Each client device can include an installed copy of a particular extension app (such as, for example, an extension app for making reservations at restaurants), and the extension app on each device can be used to create content (e.g. text, images, audio, video, etc.), and this content is passed, through an interprocess communication framework to the messaging app on the device for a specific message, which can be referred to as a message bubble, in the message transcript on the particular client device. The message app receives the content (and optionally other data from the extension app, including for example an identifier of the extension app, a resource locator and optionally metadata for use by a counterpart or remote extension app on the other device, etc.) and displays the displayable content (such as an image of a restaurant provided by the extension app which is a restaurant reservation app such as “Open Table” in the message bubble in the message transcript). In effect, the messaging app hosts a view within the messaging app and the content of that view is provided by the extension app. The resource locator and metadata in one embodiment are opaque to the messaging app (e.g. cannot be recognized by the messaging app) but can be used by the extension apps on each device to maintain state information for the session between the extension apps, and the messaging apps on each device act as a communication mechanism between the extension apps by passing the resource locator and metadata between the extension apps. In one embodiment, state information about the session may be encoded in the resource locator or may be provided in the metadata or may be in both. In one embodiment, the content created from a session on each device is displayed within the same single message bubble (identified by a session identifier that can be maintained by the messaging app) in the message transcripts, and each time the content changes (based on changes from either device), the updated content continues to be displayed within a single message bubble in the message transcript and any prior message bubbles that displayed content in the session can be converted into breadcrumbs, and these prior message bubbles will also include the same session identifier as the new, updated message bubble. The operations and functions of the components shown in  FIG. 8  will now be described while referring to  FIG. 9A  which shows a method of operating the messaging system  400  in one embodiment. 
     In operation  451  of  FIG. 9A  an extension app, such as the extension app  407  can create content and generate a resource locator and data (or can modify existing content, resource locator or data). The extension app can be similar to the extension app  83  and is executing in one embodiment in one process while the messaging app, which can be similar to the messaging app  76 , is executing in another process and communication between the processes occurs through an IPC, such as the IPC  81  which can be a software framework or library for providing interprocess communication between two distinct processes. The extension app  407  can be, for example, a restaurant reservation app that creates a reservation through a website that can provide a state information for use with the resource locator (or the state information can be encoded into the resource locator). In one embodiment, the data provided with the resource locator can be a state information provided from the website, and the state information can include information about the particular restaurant and the time of the reservation and the number of people in the reservation. The extension app  407  can present, in either a compact view or expanded view the user interface for making the restaurant reservation through the website while the remainder of the messaging app is displayed, including for example the message transcript. Thus the user of the extension app  407  can see the context of the conversation in the message transcript while interacting with the extension app and the website (through the extension app) to create a restaurant reservation. In one embodiment, the user may be able to browse through various restaurants (within the restaurant reservation app) and search for restaurants. After the user of the extension app  407  has selected a restaurant and entered a reservation, the extension app  407  can pass, through the IPC  415 , content and also the resource locator and data  417  shown in  FIG. 8  for the messaging app on device  401 . This is shown as operation  453  in  FIG. 9A . In operation  455 , the messaging app  409  associates the content received from the extension app  407  with the message bubble and displays content in the bubble in the message transcript in the user interface of the messaging app  409 . Then in operation  457 , the messaging app  409 , in response to a send command received from the user, sends a message (if any) and content received from the extension app  407 , and an app identifier which identifies the app  407  (and optionally an icon of the app  407 ), and the resource locator and the data (if any) and a session identifier to the second device through the one or more messaging servers  403  which pass the communication  419  to the second device  405  (also referred to as client device  405 ). In one embodiment, the operations  453  and  455  can occur as part of operation  457  in response to the messaging app receiving the selection of the send command. The icon of the app  407  can be displayed on the message bubble on the receiving device even if the counterpart extension app is not installed; see for example, icon  87  in  FIG. 3B . In operation  459  shown in  FIG. 9A , the messaging app  411  on the client device  405  receives the content from the one or more messaging servers  403  and displays the content in the identified message bubble  421  within the message transcript provided by the user interface of the messaging app  411 .  FIG. 9B  shows a more detailed example of such a message bubble  471  having content created by a restaurant reservation extension app in one embodiment. In the example shown in  FIG. 9B , the content includes the name of the restaurant, the time of the reservation and the number of persons of the reservation. In one embodiment, this content can be displayed by the messaging app without requiring that the extension app  413  be launched. In one embodiment, the extension app  413  is not launched until the user of client device  405  selects the message bubble  421 , thereby indicating to the client device that the user of the client device  405  intends to interact with the content in the message bubble  421 . In an alternative embodiment, the extension app  413  can be launched upon receipt by the messaging app  411  of the content but remain in the background and be ready for execution when the user of client device  405  enters a command to cause the extension app to appear. In operation  461 , the extension app  413 , which is identified by the app identifier provided in the communication  419  is launched, if not already launched, in response to selection of message bubble  421  and the messaging app  411  passes, through IPC  423  the content associated with message bubble  421  and resource locator and data  425  to the messaging app  413 . In one embodiment, the extension app  413  is the counterpart extension app that is the same extension app as extension app  407 , while in another embodiment they can be merely compatible in that they can process the same type of content. 
     At this point, the extension app  413  can receive user input by the user of client device  405  and can modify one or more of the content, the resource locator or the data. For example, the user of client device  405  can cause the extension app  413  to access one or more websites to make a modified restaurant reservation by modifying the time, the number of people, the particular restaurant, etc. In one embodiment, the extension app  413 , and also the extension app  407  can interact directly (but separately and independently) with the web server by sending the resource locator and the data to the web server and receiving responses from the web server which may include modified data or modified resource locators, or new data and/or new resource locators etc. In one embodiment, the web server can store data for use during the session, and this stored data can include information for some or all of the state information that can also be maintained by the two extension apps in the session. Again, if the extension app  413  is presented for display in a compact view, then the user of the device  405  can interact with the extension app  413  to make the restaurant reservation while the context and conversation of the chat or messaging session is shown in the message transcript of the messaging app  411 . The user of the client device  405  can scroll through the message transcript while continuing to look at and interact with the extension app  413 . Thus, the extension app  413  can, in operation  463  receive user input and may modify at least one of the content, the resource locator or data, and then can pass, in operation  465  the resource locator and data  427  (which may be modified or new) to the messaging app  411 . In turn, the messaging app  411  in operation  467  can send the content, which may be modified, and the app identifier and the resource locator (which may be modified) and data (which may be modified) and the bubble ID back to the client device  401 . As shown in operation  469 , this process can repeat over time as the two users work on setting up a restaurant reservation in the example provided herein. 
     It will be appreciated that many different types of extension apps can provide a collaborative environment between the users of client devices  401  and  405  to exchange information and collaborate together and that restaurant reservation is one such type. Thus, it will be appreciated that the restaurant reservation example that is described relative to  FIGS. 8 and 9A  is merely an example of one such type of extension app which can provide a collaborative environment in the context of the user interface of a messaging app. Examples of other types of extension apps which can provide a similar collaborative environment include, for example: sticker extension apps; imaging apps; drawing apps; content creation apps; games; music creation apps; content consumption apps; polling apps; map apps; etc. 
     The collaborative environment shown in  FIG. 8  and described relative to  FIG. 9A  can utilize breadcrumbs in one or more embodiments, and each of the breadcrumbs can be identified by a session identifier. A breadcrumb represents a converted message bubble and is identified by a session identifier that is shared with other message bubbles in the session. Each prior message bubble that is identified with the same session identifier as a new message bubble can be converted in one embodiment into a breadcrumb which can appear differently than the original content shown in the message transcript. As each new message bubble in the session arrives or is added to the message transcript, the prior message bubble identified with the same session identifier can be converted into a breadcrumb in one embodiment, and this is shown in the message transcripts shown in  FIGS. 9D, 9E, 9F, 9G, and 9H .  FIGS. 9D and 9H  show a message transcript  510  on Joe&#39;s device, and  FIGS. 9E, 9F, and 9G  show a message transcript  17  on Lester&#39;s device. Message transcript  510  shows Lester&#39;s user name  511 , and message transcript  517  shows Joe&#39;s user name  518 . In the example shown in  FIGS. 9D, 9E, 9F, 9G, and 9H , Lester and Joe are engaged in a text messaging conversation and are each using an extension app, such as an image creation app or other extension apps. For example, Lester can be using extension app  407  shown in  FIG. 8  and Joe can be using extension app  413  shown in  FIG. 8 . Lester&#39;s device can be using messaging app  409  while Joe&#39;s device can be using messaging app  411 . Referring back to  FIG. 9D , it can be seen that the message transcript  510  includes message bubble  512  and message bubble  513  which indicate the content of the conversation within the message transcript  510 . In addition, Joe has used the extension app  413  to create content  515  which is appended to message bubble  514 . For example, Joe may have entered text as a text message and also created content using the extension app  413  and then cause both the text shown within message bubble  514  and the content  515  to be sent to Lester&#39;s device. The right side of the message transcript  510  shows messages that were sent by Joe while the left side of the message transcript  510  shows messages that were received from Lester. Referring now to  FIG. 9E , it can be seen that message bubble  513  is now on the right side of the message transcript  517  while message bubble  514  and content  515  are on the left side of the message transcript  517  on Lester&#39;s device. Hence, Lester&#39;s device has received the text message within message bubble  514  and has also received the content generated by the extension app on Joe&#39;s device. Lester can then tap on the content  515  to cause the launching of the corresponding or counterpart extension app on Lester&#39;s device. The content  515  is associated with a session identifier which is maintained for the extension app on Lester&#39;s device. For example, at this point in the process, operation  461  shown in  FIG. 9A  can be performed on Lester&#39;s device as a result of the user selecting the content  515  which can be displayed within a message bubble in one embodiment. Lester can then use the extension app on Lester&#39;s device to create modified content or new content and send that modified or new content back to Joe. In  FIG. 9F , it can be seen that Lester has created modified or new content  521  which is shown within a staging area  519  which shows text and other content that is ready to be sent and will be sent in response to selection by a user of a send command, such as the send button  523  shown in  FIG. 9F . When Lester selects the send command with the content shown in the staging area  519 , this causes the text message  520  and the new or modified content  521  to be sent to Joe, and this can be seen in  FIG. 9G  in which message bubble  521 A shows the text message  520  on the right side of the message transcript  517  which also shows the content  521  which was modified or created as new by Lester using the extension app  407  on Lester&#39;s device. 
     It can be seen from  FIG. 9G  that content  515  has now been converted into a breadcrumb  515 A. This conversion in one embodiment can be performed by the messaging app or alternatively by the extension app. In one embodiment, the extension app can provide the text which appears within the breadcrumb  515 A, and the messaging app will use the session identifier to identify the message bubble that will be converted into a breadcrumb and this will cause the conversion of content  515  into the breadcrumb  515 A and display the breadcrumb next to the associated message bubble  514  without converting that message bubble  514  into a breadcrumb in one embodiment. Thus,  FIG. 9C  shows how a session identifier associated with prior message bubbles or content created by an extension app can be used to convert the prior message bubble(s) into a breadcrumb on a sending device.  FIG. 9H  shows how the conversion is displayed in one embodiment on the receiving device. In the figure shown in  FIG. 9H , the message bubble  520 A is shown on the left side of the message transcript  510  along with the new or modified content from extension app  403  from Lester&#39;s device. The content  515  on Joe&#39;s device has been converted into a breadcrumb  515 A on the right side of the message transcript and is displayed adjacent to the message bubble  514  which accompanied the content  515  when the content  515  was originally sent. 
     If the receiving device, such as client device  405  in operation  459  is capable of installing and using the extension app (identified by the app identifier provided in communication  419 ) but that the extension app is not installed on the receiving device, the receiving device can, within the user interface of the messaging app offer to download and install the extension app (again specified by the app identifier in communication  419 , on the receiving device).  FIG. 9C  shows an example in which the content from extension  407  can be displayed on the client device  405  in a message bubble  471  and the client device  405  is in the process of downloading and installing the extension app identified by the app identifier in communication  419 . In the example shown in  FIG. 9C , the content is displayed within the message bubble  471  while the extension app  413  is being installed. In one embodiment, a progress bar  473  (or alternatively a progress circle) can be shown within the message bubble  471  during the installation process. In one embodiment, the downloading and installation process can be performed in the background while the messaging app remains the foreground application. If the receiving device is not capable of installing or using the extension app, then the resource locator and the metadata can be passed in one embodiment to a web browser on the receiving device, and the web browser can become the foreground app and allow for the user interaction with the web page referred to by the resource locator. 
     In some embodiments, it may be desirable to provide an identifier of each user to each extension app executing on a client device, particularly in the case of a collaborative environment in which two or more users are interacting through the messaging apps and the extension apps.  FIG. 10  shows an example of a method to provide an identifier for each extension app without causing a loss of the user&#39;s privacy. The method shown in  FIG. 10  can be performed by each messaging app on each client device. In one embodiment, the method can be performed in response to a call from an extension app to an application programming interface (API) which can allow the extension app to request an identifier of the local user. In one embodiment, the identifier can be the local user&#39;s email address or phone number or other identifier used by the messaging system. The identifier provided to the extension app is an obfuscated identifier created, in one embodiment, by the method shown in  FIG. 10 . In operation  501 , the messaging app can generate, in response to a call from the extension app, a salt for the particular extension app. In one embodiment, the salt can be a random number which is associated with that particular extension app. Then in operation  503 , the messaging app can generate a hash (such as a SHA-1 hash) of a combination of a user or device identifier and the salt. For example, the user identifier may be the phone number or email address of the user and that phone number or email address is combined with the salt and then the hash is created for that combination in operation  503 . Then in operation  505 , the hash is provided, through the IPC, to the extension app, and that hash value can be used as data with the resource locator which can then be sent to the other extension app to identify the user that has made changes or has created a content. In another embodiment, the messaging app can obfuscate the identifier by maintaining a mapping of the identifier and a randomly generated unique identifier for each extension app. In other words, for a given extension app, the messaging app can generate a random (and unique) identifier for the extension app and associate (e.g., map) that random identifier with the identifier of the user (e.g. local user&#39;s email address or phone number or other identifier used by the messaging system). This random identifier for the given extension app can be provided to the extension app, but the identifier is not provided to the extension app. Another extension app would receive a different, randomly generated identifier. This extension app specific identifier can then be provided to a counterpart extension app on another device so that the two extension apps can keep track of which users performed which actions in the context of a session or other collaborative environment. 
     In one embodiment, the messaging systems described herein can provide confirmation of receipt of messages to one or more extension apps, and this may be useful in certain cases in which the extension app needs to be assured that the remote extension app has the same known state as the local extension app.  FIG. 11  shows an example of a method for providing confirmation of receipt. In operation  551 , the messaging app receives the “send” command from a user and in response the local extension app provides the content to the messaging app. In turn, in operation  553 , the messaging app sends the message and message bubble identifier and content and resource locator (if any) through the one or more messaging servers to a receiving device which also includes a message app. At some point, the messaging app on the local device in operation  555  receives a confirmation of receipt of the message and content and optional resource locator, and then can pass, in operation  557 , through the IPC the confirmation of receipt to the local extension app so that the local extension app knows that the remote extension app has the same known state when the extension app provided its content for transmission to the remote extension app. 
       FIG. 12  shows another aspect to the embodiments described herein, and that aspect relates to the presentation of multiple message bubbles within a message transcript where different message bubbles have content created by different extension apps, and at least one of which may be executing (and have its content displayed in a compact view) while the message transcript of the user interface of the messaging app is also displayed.  FIG. 12  shows an example of such an aspect. The communication device  600  in this embodiment includes a touch screen  601  which displays a message transcript  603  which includes two message bubbles  605  and  607 . In addition, the messaging app presents a compact view  609  of an extension app, which in this case is an extension app for a restaurant reservation. In the example shown in  FIG. 12 , the extension app for a restaurant reservation has been used to send a message showing the content of a restaurant reservation, which is depicted as message bubble  607 . This may have occurred as a result of receiving a message from another user who uses another communication device which provides the content of a restaurant review from another extension app. In the example shown in  FIG. 12 , message bubble  605  shows the content created by a remote extension app for providing restaurant reviews which is different than the extension app for making a restaurant reservation. In one embodiment, both extension apps may be executing on both communication devices that are part of the messaging session or chat. 
     Another aspect of the embodiments described herein relate to backward compatibility, and that aspect is shown in  FIGS. 13A and 13B . Certain older devices may not be compatible with the extension app architecture described herein or may not use this architecture or may not even be smartphones. In one embodiment, a client device which is sending the message may be able to provide alternative content, either automatically or based upon a determination that the receiving device is not compatible with extension app. A method for providing backward compatibility is shown in  FIG. 13A . In operation  651 , an extension app on a sending device creates content on the sending device (first device) for delivery to a second device through a messaging app and a messaging service. This can be similar to operation  451  in  FIG. 9A . The content created in operation  651  can then be passed through an interprocess communication to the messaging app in operation  653  in response to the messaging app receiving the user&#39;s “send” selection. Then in operation  655 , the messaging app can display the content on the first device and also determine that the second device is not compatible with extension apps. In one embodiment, this can be determined as a result of receiving information about the receiving device (second device) from one or more messaging servers, such as the one or more messaging servers  51  shown in  FIG. 2  which can maintain information about the state of each device, such as the version of the operating system of the device or the type of device, etc. As a result of determining that the second device is not compatible with extension apps, the messaging app can in operation  657  send alternative content to the second device, and  FIG. 13B  provides an example of this alternative content. 
     The communication device  675  shown in  FIG. 13B  may be, for example, an older smartphone which uses an older operating system that is not compatible with extension apps described herein. Nevertheless, the communication device  675  includes a touch screen  679  and a text entry region  683  and an on-screen keyboard  685  that provide functionality of a messaging app which also displays a message transcript  681  which includes a message bubble  687 . The message bubble  687  contains the alternative content provided by a sending message app on a remote device. In this case the content includes an image  689  and a resource locator  691  which may be user selectable to cause the display of a web page which the resource locator  691  refers to. In other words, the resource locator  691  may be user selectable to invoke a web browser on the communication device  675  to allow the user of the communication device  675  to interact through a web browser with the web page which may have the same affect in certain instances as an extension app interacting with the website. 
     Another aspect of the embodiments described herein relate to a service, such as an app marketplace that can provide a plurality of different extension apps for use within a messaging app according to the one or more embodiments described herein. The service or app marketplace can present browsable views of the plurality of different extension apps and messaging app plug-ins and provide information about those various extension apps and provide for downloading of those extension apps to a client device to allow the client device to install one or more extension apps.  FIG. 14A  shows an example of a method for using such a service or app marketplace and  FIG. 14B  shows an example of a user interface for a messaging extension app marketplace. The app marketplace shown in  FIG. 14B  may be invoked in one embodiment from a browsable view of installed extension apps within the user interface of the messaging app on a client device. For example, the selection of icon  167  shown in  FIG. 4B  may cause the presentation of the messaging extension app marketplace shown in  FIG. 14B . The user can then browse through the one or more collections of messaging extension apps and select one or more extension apps which may be free or may be purchased. In the example shown in  FIG. 14B , the messaging extension app marketplace  725  can include a navigation bar  729  and a browsable view of one or more messaging extension apps, such as apps  726 ,  728 , and  731  displayed on the touch screen  727 . The user can browse through the apps by swiping, in one embodiment, the user&#39;s finger across the touch screen or by the use of a navigation bar  729 . The user can then select the download and install one or more of the extension apps, and as a result the messaging app on the user&#39;s client device can add an icon representing the newly installed extension app into the browsable view of installed extension apps, such as the browsable view  157  shown in  FIG. 4B . In addition, the messaging app can add the installed extension app into a list of installed extension apps along with the identifier of the app (“app identifier”) provided by the app marketplace. While the user&#39;s use of the app marketplace shown in  FIG. 14B  is one way of installing extension apps, another way is shown in  FIG. 14A  in which the installation process begins as a result of the user interacting with a message in the message transcript of a messaging app. 
     Referring now to  FIG. 14A , a messaging app in operation  701  can receive content (and an optional resource locator and data) created by an extension app on a remote device, such as a first device, and can also receive an app identifier of the extension app on the remote device. In one embodiment, the app identifier can be the same identifier provided by the app marketplace when the extension app was installed on the first device or can be a different identifier that is associated with the app store&#39;s identifier. Then in operation  703 , the messaging app on the second device can display the content in a message bubble and can retain the resource locator and data if provided. At this point, the messaging app in this embodiment does not attempt to launch an extension app which in fact is not installed on the second device at this point in time. Then in operation  705 , the messaging app receives a selection, such as a tap, of the message bubble containing the content provided by the extension app from the first device, and the messaging app determines that the extension app (as identified by the received app identifier) is not installed on the second device. At this point, as shown in operation  707  of  FIG. 14A , the messaging app offers to download and install the extension app on the second device and the user can select to install that extension app which was identified by the app identifier received in operation  701 . In some instances, the user may need to purchase the extension app before it can be downloaded and installed. The offer to download and install may be presented in a notice, such as the notice  259  shown in  FIG. 5F , and this notice may include a selectable option to cause the downloading and the installing of the extension app for the selected message bubble. Then in operation  709 , the second device downloads and installs the extension app and can launch the newly installed extension app. In one embodiment, the download and install can occur in the background while the messaging app remains the foreground. In one embodiment, the progress of the download and install can be shown in a progress bar, such as the progress bar  473  shown within the selected message bubble. After operation  709  is completed, then the newly installed extension app can be used on the second device and, the messaging app can provide, in operation  711 , the content and optional resource locator and data to the extension app on the second device within the view hosted by messaging app. 
     In one embodiment, the messaging app may cause the automatic updating of extension apps which have been installed. In another embodiment, the messaging app may provide alerts or notices to the user that certain extension apps are in need of being updated and the notifications about these updates can be received from an extension app marketplace in one embodiment. This can allow a user to selectively decide whether or not to update specific messaging apps. 
     Another aspect of the embodiments described herein relate to a music creation app that can operate with a text messaging app either as a plug-in of the text messaging app or as an extension app of the text messaging app such that a user interface of the music creation app is displayed in a view which is hosted by the text messaging app. In one embodiment, the music creation app can allow for a participant in a conversation using the messaging app to collaborate with another participant using a messaging app and another music creation app. For example, the two users may collaborate on a song snippet or full song which can include one or more tracks of musical content. From within a text messaging app, a user can invoke the music creation app to bring up a music creation user interface and create one or more tracks of a song, either by playing a simulated musical instrument or by making a live recording (e.g. singing, playing a musical instrument, or playing a musical instrument that is coupled through a wired or wireless interface with the device that is executing the text messaging app). Once the user is done, the user can send the song or other musical composition as music data through the first messaging app to another participant or other participants in the conversation who can see the music data displayed in their message transcripts provided by their messaging apps. For example, each participant can see the song as a message bubble within their message transcript and they can play the song by tapping on the message bubble even if, in one embodiment, a counterpart music creation app is not installed on their device. If their device does include a counterpart music creation app, then the other participants can add another track or modify an existing track. The additional track can play along with the existing track or extend the existing track. The modified music data created by the second user can then be sent back as a reply to the first device, and this collaborative process can continue, each time with someone adding a track or modifying one of their previously added tracks until the song is finished. In one embodiment, the finished song can be saved in non-volatile memory (e.g. flash memory) for future use with the music creation app or other music creation apps. In another embodiment, the finished song can be exported as an audio recording to make it possible to share with others who do not have the music creation app. 
     A description of the methods performed according to one embodiment on the first and second device which are involved in the collaboration will now be provided while referring to  FIGS. 15A and 15B .  FIG. 15A  shows a method performed by a first device which, in operation  1001 , displays a first messaging app on the first device, wherein the first messaging app is configured to communicate text messages to at least a second messaging app on a second device. In operation  1003 , the first messaging app receives a command to display a music creation app within a view hosted by the first messaging app. In one embodiment, this command can be a user&#39;s selection of an icon of the music creation app in a browsable view, such as browsable view  157 , of the first messaging app; or, the command can be the result of a user&#39;s selection of a message bubble containing data created by a music creation app, such as the music creation app on the first device or the music creation app on the second device (the second music creation app). In response to the command received in operation  1003 , the first device in operation  1005  displays a user interface of the music creation app within a view hosted by the first messaging app. In one embodiment, the user interface of the music creation app is configured to receive one or more inputs to create music. For example, the music interface could be similar to the user interface of the application program known as GarageBand which is available from Apple Inc. of Cupertino, Calif. The GarageBand application can operate on Macintosh computers and on iOS devices and includes a variety of ways of creating music. For example, the application can receive inputs on a simulated musical instrument which can be displayed in the user interface of the music creation app. Further, it can receive inputs to create music such as recording a user or user&#39;s singing or playing musical instruments. Moreover, in one embodiment, a music creation app may also be able to receive music data through a wired or wireless interface from physical musical instruments, such as MIDI musical instruments, etc. In addition, the music creation app may also be able to accept inputs in the form of entry of musical notes on a musical score in one embodiment. 
     Thus operation  1005  allows a user to create music in a variety of ways, and this created music can then be sent to a text messaging app in operation  1007 . If the music creation app is an extension app, then the music creation extension app will pass music data through an interprocess communication to the first messaging app in response to a send selection which can be received in operation  1007 . If the music creation app is a plug-in of the first messaging app, the first messaging app should already have the music data because the plug-in normally operates in the same process as the first messaging app. The first messaging app in operation  1007  can send music data, such as one or more music files in an appropriate format, such as a GarageBand file format or other formats known in the art for providing music data. Also, the first messaging app in operation  1007  can optionally send one or more of an audio file and a graphic file depicting one or more music tracks to the second messaging app. In one embodiment, the audio file may be a conventional audio file having any one of the standard audio formats that can be played back on most devices; for example, the audio file can be an MP3 file or other known formats that can allow for the playback of audio. The graphic file can depict one or more music tracks in formats that are known in the art, and a portion at least of this graphic file can be depicted within a message bubble in a message transcript displayed by both the first messaging app and the second messaging app. 
     After operation  1007 , the first device can receive from the second messaging app modified music data which was created by a counterpart music app, such as the second music creation app described in conjunction with  FIG. 15B . The modified music data may be a modified existing track or an additional track or other modifications. In response to the receipt of the modified music data, the first messaging app in operation  1011  converts the prior music message bubble which was shown in the message transcript displayed by the first messaging app into a breadcrumb and creates a new music message bubble in a session which is identified with a session identifier that also identifies the prior music message bubble which has been converted into a breadcrumb. The new music message bubble can include prior and/or new or modified music content within the new music message bubble, such as message bubble  1123  shown in  FIG. 16K . 
     After operation  1017 , the user of the first device can select that new message bubble and then continue to collaborate in the creation of the song, causing the first device to return back to operation  1005  to allow the process or method to repeat throughout the collaboration of the song. 
       FIG. 15B  shows a method performed on a second device which includes the second messaging app that is involved in the collaboration of the song with the first device described relative to  FIG. 15A . In operation  1025 , the second messaging app receives music data from the first messaging app. The receipt of this music data results from the sending in operation  1007  shown in  FIG. 15A . In operation  1027 , the second messaging app displays content derived from the music data, and this content is displayed within a message bubble in a message transcript that is displayed by the second messaging app. In operation  1029 , the second messaging app can receive a selection of the message bubble displayed by operation  1027 . For example, the user of the second messaging app can tap on or otherwise select the message bubble. In one embodiment, the selection in operation  1029  causes the launching of the second music creation app, which can then display in operation  1031  a user interface of the second user creation app within a view hosted by the second messaging app (see, for example,  FIG. 16J ). The second music creation app referred to in operation  1031  can be the same as the counterpart music app referred to in operation  1009  in  FIG. 15A . If the second music creation app is an extension app of the second messaging app then the second messaging app will pass the received music data through an interprocess communication to the second music creation app so that the second music creation app can display its user interface with the music data. After the user interface of the second music creation app has been displayed, the second music creation app in operation  1033  can receive one or more user inputs to modify the music data received from the first messaging app. After the user of the second music creation app is satisfied with the modified music data, the music data can be sent to the first messaging app in response to a send command from the user of the first messaging app. If the second music creation app is an extension app, then the second music creation app will pass the modified music data through the interprocess communication to the second messaging app which can then send the modified music data. In one embodiment, the passing of the modified music data through the interprocess communication does not occur until the user selects the send command in operation  1035 . The modified music data is then sent in operation  1037 , and that modified music data which was sent in operation  1037  corresponds to the modified music data which was received in operation  1009  in  FIG. 15A  in one embodiment. 
     In operation  1039 , the second messaging app creates a breadcrumb of the prior music message bubble in a session, and both the prior and current music message bubbles are labeled with a session identifier which is the same for all message bubbles that are part of the session. In one embodiment, a message bubble is replaced with a breadcrumb when a later message bubble identified with the same session identifier includes new or modified content. 
       FIGS. 16A-16K  show examples of user interfaces on two devices which in one embodiment can perform the method shown in  FIGS. 15A and 15B .  FIGS. 16A, 16B, 16C, 16D, 16E, 16F, 16G, and 16K  show a user interface of a first device  1101  which can perform the method shown in  FIG. 15A , and  FIGS. 16H, 16I, and 16J  show a user interface of a second device  1117  which can perform the method shown in  FIG. 15B . 
     The sequence of events for the collaboration of a song can begin as shown in  FIG. 16A  in which the user of the first device  1101  has sent a message, shown in message bubble  1103  to the user (Alice) of the second device  1117 . Alice has replied to the message shown in message bubble  1103  with the message shown in message bubble  1105  (I&#39;d love to hear it!). This conversation between two users each using a respective text messaging app on their device has caused Ian, the user of the first device  101 , to launch a music creation app on the first device  1101  by accessing an icon representing the music creation app through the sequence of user interfaces shown in  FIG. 16B  and  FIG. 16C . In particular, the user of the first device  1101  has caused the display of the onscreen keyboard  1107  as shown in  FIG. 16B , from which (in this embodiment) Ian can select an icon to cause the presentation of a browsable view, such as browsable view  157 , to present a music creation icon such as music creation icon  1109  as shown in  FIG. 16C , which can be displayed in a tray or drawer. If the user selects the icon of the music creation app within the tray or drawer, this causes the launching of the music creation app which can then present, as shown in  FIG. 16D , a user interface of the first music creation app. In particular, user interface  1111  shows (in a compact view) a sequence of different instruments which the user can select. In this particular example, the user selects a piano keyboard as the simulated musical instrument, and the user of the first music creation app will use that keyboard to create music. In the example shown in  FIG. 16E , the user of the first device  1101  has rotated the device into a landscape orientation. The user interface  1111 A of the first music creation app is now receiving user inputs (from Ian) to create a first track for the song. In particular, Ian will tap the keys displayed in the user interface to create the song. In the example shown in FIG.  16 E, Ian has tapped the F key shown on the keyboard at this point in time for the song. After completing or while working on the song, Ian can display a track graphic, such as track graphic  1112  shown in  FIG. 16F . After the user of the first device  1101  is satisfied with the song, the user can cause music data for the song to be sent by the text messaging app by selecting a send command within a user interface of the text messaging app. It will be understood that even in landscape mode as shown in  FIGS. 16E and 16F , the music creation app is still displayed within a view hosted by the first messaging app. 
       FIG. 16G  shows the user interface of the first device after the music data has been sent by the first messaging app. Thus,  FIG. 16G  corresponds to the result of operation  1007  after the music data has been sent by the first messaging app. In those embodiments in which the first music creation app is an extension app, the music creation app will pass the music data through an interprocess communication to the first messaging app which can then send the music data to the second messaging app on the second device  1117 . The music message bubble  1114  includes a play button  1115  which the user of the first device  1101  can use to cause the playback of the audio of the song. In addition, the music message bubble  1114  includes a portion of the track graphic  1112  and also includes an icon of the music creation app (shown in the lower right portion of the music message bubble  1114 ). 
       FIGS. 16H, 16I, and 16J  show the user interfaces at different points in time on the second device which is Alice&#39;s device which has received the music data for the song created by Ian through the use of the user interface  1111 A shown in  FIG. 16E . Thus, as shown in  FIG. 16H , the music message bubble  1114 , displayed on the left side of the message transcript on second device  1117 , includes a pause button  1115 A indicating that Alice has selected the play button  1115  and has caused the second device  1117  to play the song on the second device  1117 . Alice responds, as shown in  FIG. 16I , with a message that indicates that she would like to sing to the song. In particular, Alice has used the onscreen keyboard  1118  on the second device  1117  to create the text message shown in message bubble  1119  and has sent that text message to the first device. The second device  1117  also includes a version of the music creation app as an installed extension app or a plug-in of the second messaging app which is providing the user interface shown in  FIGS. 16H, 16I, and 16J . As shown in  FIG. 16J , Alice has caused the second music creation app to be launched and has selected the audio recorder (displayed in the compact view of the second music creation app) as the form of input that will be used to create a second track which will be added to the track created by Ian. Alice can launch the second music creation app in one embodiment by tapping on a portion of the music message bubble  1114  other than the play button  1115 . For example, Alice can tap on the track graphic shown in the music message bubble  1114  or can tap on the icon of the music creation app shown in the lower right portion of the music message bubble  1114 . The selection which causes the launching of the second music creation app can alternatively be a selection of the music creation app&#39;s icon in a browsable view of installed apps, such as the browsable view  157 . 
     Alice can use the user interface  1121  of the second music creation app to record her singing to the song created by Ian, and once she has completed her singing, she can send her singing, which is now a second track that plays along with the first track from Ian when the song is played back. The modified music data will now include both tracks that play concurrently together. 
       FIG. 16K  shows the result on the first device  1101  after Alice sends the modified music data back to the first device  1101 . Message bubbles  1103 ,  1105 , and  1119  remain as before but the music message bubble  1114  has been converted into a breadcrumb  1114 A as a result of being identified with a session identifier that also matches the session identifier for the music message bubble  1123 . The music message bubble  1123  now includes a first track graphic  1124  and a second track graphic  1125 . In addition, the music message bubble  1123  includes text which indicates the last action which occurred to the song, which in this case was Alice adding vocals. The first track graphic  1124  corresponds to the track created by Ian, while the track graphic  1125  corresponds to the track created by Alice through the use of user interface  1121  shown in  FIG. 16J . 
     The sending by Alice of her singing through the user interface shown in  FIG. 16J  corresponds to operation  1037  shown in  FIG. 15B , and the modified music data is received in operation  1009  in  FIG. 15A . This collaboration process can continue over time allowing each user to modify or add tracks during the collaboration, and as a result the methods shown in  FIGS. 15A and 15B  will repeat during that collaboration process. 
     One or more Application Programming Interfaces (APIs) may be used in some embodiments. An API is an interface implemented by a program code component or hardware component (hereinafter “API-implementing component”) that allows a different program code component or hardware component (hereinafter “API-calling component”) to access and use one or more functions, methods, procedures, data structures, classes, and/or other services provided by the API-implementing component. An API can define one or more parameters that are passed between the API-calling component and the API-implementing component. 
     An API allows a developer of an API-calling component (which may be a third party developer) to leverage specified features provided by an API-implementing component. There may be one API-calling component or there may be more than one such component. An API can be a source code interface that a computer system or program library provides in order to support requests for services from an application. An operating system (OS) can have multiple APIs to allow applications running on the OS to call one or more of those APls, and a service (such as a program library) can have multiple APIs to allow an application that uses the service to call one or more of those APIs. An API can be specified in terms of a programming language that can be interpreted or compiled when an application is built. 
     In some embodiments the API-implementing component may provide more than one API, each providing a different view of or with different aspects that access different aspects of the functionality implemented by the API-implementing component. For example, one API of an API-implementing component can provide a first set of functions and can be exposed to third party developers, and another API of the API-implementing component can be hidden (not exposed) and provide a subset of the first set of functions and also provide another set of functions, such as testing or debugging functions which are not in the first set of functions. In other embodiments the API-implementing component may itself call one or more other components via an underlying API and thus be both an API-calling component and an API-implementing component. 
     An API defines the language and parameters that API-calling components use when accessing and using specified features of the API-implementing component. For example, an API-calling component accesses the specified features of the API-implementing component through one or more API calls or invocations (embodied for example by function or method calls) exposed by the API and passes data and control information using parameters via the API calls or invocations. The API-implementing component may return a value through the API in response to an API call from an API-calling component. While the API defines the syntax and result of an API call (e.g., how to invoke the API call and what the API call does), the API may not reveal how the API call accomplishes the function specified by the API call. Various API calls are transferred via the one or more application programming interfaces between the calling (API-calling component) and an API-implementing component. Transferring the API calls may include issuing, initiating, invoking, calling, receiving, returning, or responding to the function calls or messages; in other words, transferring can describe actions by either of the API-calling component or the API-implementing component. The function calls or other invocations of the API may send or receive one or more parameters through a parameter list or other structure. A parameter can be a constant, key, data structure, object, object class, variable, data type, pointer, array, list or a pointer to a function or method or another way to reference a data or other item to be passed via the API. 
     Furthermore, data types or classes may be provided by the API and implemented by the API-implementing component. Thus, the API-calling component may declare variables, use pointers to, use or instantiate constant values of such types or classes by using definitions provided in the API. 
     Generally, an API can be used to access a service or data provided by the API-implementing component or to initiate performance of an operation or computation provided by the API-implementing component. By way of example, the API-implementing component and the API-calling component may each be any one of an operating system, a library, a device driver, an API, an application program, or other module (it should be understood that the API-implementing component and the API-calling component may be the same or different type of module from each other). API-implementing components may in some cases be embodied at least in part in firmware, microcode, or other hardware logic. In some embodiments, an API may allow a client program (e.g., game center application) to use the services provided by a Software Development Kit (SDK) library. In other embodiments an application or other client program may use an API provided by an Application Framework. In these embodiments the application or client program may incorporate calls to functions or methods provided by the SDK and provided by the API or use data types or objects defined in the SDK and provided by the API. An Application Framework may in these embodiments provide a main event loop for a program that responds to various events defined by the Framework. The API allows the application to specify the events and the responses to the events using the Application Framework. In some implementations, an API call can report to an application the capabilities or state of a hardware device, including those related to aspects such as input capabilities and state, output capabilities and state, processing capability, power state, storage capacity and state, communications capability, etc., and the API may be implemented in part by firmware, microcode, or other low level logic that executes in part on the hardware component. 
     The API-calling component may be a local component (i.e., on the same data processing system as the API-implementing component) or a remote component (i.e., on a different data processing system from the API-implementing component) that communicates with the API-implementing component through the API over a network. It should be understood that an API-implementing component may also act as an API-calling component (i.e., it may make API calls to an API exposed by a different API-implementing component) and an API-calling component may also act as an API-implementing component by implementing an API that is exposed to a different API-calling component. 
     The API may allow multiple API-calling components written in different programming languages to communicate with the API-implementing component (thus the API may include features for translating calls and returns between the API-implementing component and the API-calling component); however the API may be implemented in terms of a specific programming language. An API-calling component can, in one embedment, call APIs from different providers such as a set of APIs from an OS provider and another set of APIs from a plug-in provider and another set of APIs from another provider (e.g. the provider of a software library) or creator of the another set of APIs. 
       FIG. 17  is a block diagram illustrating an exemplary API architecture, which may be used in one embodiment of the present invention. As shown in  FIG. 17 , the API architecture  3200  includes the API-implementing component  3210  (e.g., an operating system, a library, a device driver, an API, an application program, software or other module) that implements the API  3220 . The API  3220  specifies one or more functions, methods, classes, objects, protocols, data structures, formats and/or other features of the API-implementing component that may be used by the API-calling component  3230 . The API  3220  can specify at least one calling convention that specifies how a function in the API-implementing component receives parameters from the API-calling component and how the function returns a result to the API-calling component. The API-calling component  3230  (e.g., an operating system, a library, a device driver, an API, an application program, software or other module) makes API calls through the API  3220  to access and use the features of the API-implementing component  3210  that are specified by the API  3220 . The API-implementing component  3210  may return a value through the API  3220  to the API-calling component  3230  in response to an API call. 
     It will be appreciated that the API-implementing component  3210  may include additional functions, methods, classes, data structures, and/or other features that are not specified through the API  3220  and are not available to the API-calling component  3230 . It should be understood that the API-calling component  3230  may be on the same system as the API-implementing component  3210  or may be located remotely and accesses the API-implementing component  3210  using the API  3220  over a network. While  FIG. 17  illustrates a single API-calling component  3230  interacting with the API  3220 , it should be understood that other API-calling components, which may be written in different languages (or the same language) than the API-calling component  3230 , may use the API  3220 . 
     The API-implementing component  3210 , the API  3220 , and the API-calling component  3230  may be stored in a machine-readable medium (e.g., computer-readable medium), which includes any mechanism for storing information in a form readable by a machine (e.g., a computer or other data processing system). For example, a machine-readable medium includes magnetic disks, optical disks, random access memory; read only memory, flash memory devices, etc. 
     In  FIG. 18  (“Software Stack”), in one embodiment of the present invention, applications can make calls to Services A or B using several Service APIs and to Operating System (OS) using several OS APIs. Services A and B can make calls to OS using several OS APIs. 
     Note that the Service  2  has two APIs, one of which (Service  2  API  1 ) receives calls from and returns values to Application  1  and the other (Service  2  API  2 ) receives calls from and returns values to Application  2 . Service  1  (which can be, for example, a software library) makes calls to and receives returned values from OS API  1 , and Service  2  (which can be, for example, a software library) makes calls to and receives returned values from both OS API  1  and OS API  2 . Application  2  makes calls to and receives returned values from OS API  2 . 
     The systems and methods described herein can be implemented in a variety of different data processing systems and devices, including general-purpose computer systems, special purpose computer systems, or a hybrid of general purpose and special purpose computer systems. Exemplary data processing systems that can use any one of the methods described herein include desktop computers, laptop computers, tablet computers, smart phones, cellular telephones, personal digital assistants (PDAs), embedded electronic devices, or consumer electronic devices. 
       FIG. 19  is a block diagram of data processing system hardware according to an embodiment. Note that while  FIG. 19  illustrates the various components of a data processing system that may be incorporated into a mobile or handheld device, it is not intended to represent any particular architecture or manner of interconnecting the components as such details are not germane to the present invention. It will also be appreciated that other types of data processing systems that have fewer components than shown or more components than shown in  FIG. 19  can also be used with the present invention. 
     As shown in  FIG. 19 , the data processing system includes one or more buses  1309  that serve to interconnect the various components of the system. One or more processors  1303  are coupled to the one or more buses  1309  as is known in the art. Memory  1305  may be DRAM or non-volatile RAM or may be flash memory or other types of memory or a combination of such memory devices. This memory is coupled to the one or more buses  1309  using techniques known in the art. The data processing system can also include non-volatile memory  1307 , which may be a hard disk drive or a flash memory or a magnetic optical drive or magnetic memory or an optical drive or other types of memory systems that maintain data even after power is removed from the system. The non-volatile memory  1307  and the memory  1305  are both coupled to the one or more buses  1309  using known interfaces and connection techniques. A display controller  1322  is coupled to the one or more buses  1309  in order to receive display data to be displayed on a display device  1323 . The display device  1323  can include an integrated touch input to provide a touch screen. The data processing system can also include one or more input/output (I/O) controllers  1315  which provide interfaces for one or more I/O devices, such as one or more mice, touch screens, touch pads, joysticks, and other input devices including those known in the art and output devices (e.g. speakers). The input/output devices  1317  are coupled through one or more I/O controllers  1315  as is known in the art. 
     While  FIG. 19  shows that the non-volatile memory  1307  and the memory  1305  are coupled to the one or more buses directly rather than through a network interface, it will be appreciated that the present invention can utilize non-volatile memory that is remote from the system, such as a network storage device which is coupled to the data processing system through a network interface such as a modem or Ethernet interface. The buses  1309  can be connected to each other through various bridges, controllers and/or adapters as is well known in the art. In one embodiment the I/O controller  1315  includes one or more of a USB (Universal Serial Bus) adapter for controlling USB peripherals, an IEEE 1394 controller for IEEE 1394 compliant peripherals, or a Thunderbolt controller for controlling Thunderbolt peripherals. In one embodiment, one or more network device(s)  1325  can be coupled to the bus(es)  1309 . The network device(s)  1325  can be wired network devices (e.g., Ethernet) or wireless network devices (e.g., WI-FI, Bluetooth). 
     It will be apparent from this description that aspects of the present invention may be embodied, at least in part, in software. That is, the techniques may be carried out in a data processing system in response to its processor executing a sequence of instructions contained in a storage medium, such as a non-transitory machine-readable storage medium (e.g. DRAM or flash memory). In various embodiments, hardwired circuitry may be used in combination with software instructions to implement the present invention. Thus the techniques are not limited to any specific combination of hardware circuitry and software, or to any particular source for the instructions executed by the data processing system. Moreover, it will be understood that where mobile or handheld devices are described, the description encompasses mobile devices (e.g., laptop devices, tablet devices), handheld devices (e.g., smartphones), as well as embedded systems suitable for use in wearable electronic devices. 
     The present disclosure recognizes that the use of personal information data, in the present technology, can be used to the benefit of users. For example, the personal information data can be used to deliver information or targeted content that is of greater interest to the user. Accordingly, use of such personal information data can enable calculated control of the delivered content. Further, other uses for personal information data that benefit the user are also contemplated by the present disclosure. 
     The present disclosure further contemplates that the entities responsible for the collection, analysis, disclosure, transfer, storage, or other use of such personal information data will comply with well-established privacy policies and/or privacy practices. In particular, such entities should implement and consistently use privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining personal information data private and secure. For example, personal information from users should be collected for legitimate and reasonable uses of the entity and not shared or sold outside of those legitimate uses. Further, such collection should occur only after receiving the informed consent of the users. Additionally, such entities would take any needed steps for safeguarding and securing access to such personal information data and ensuring that others with access to the personal information data adhere to their privacy policies and procedures. Further, such entities can subject themselves to evaluation by third parties to certify their adherence to widely accepted privacy policies and practices. 
     Despite the foregoing, the present disclosure also contemplates embodiments in which users selectively block the use of, or access to, personal information data. That is, the present disclosure contemplates that hardware and/or software elements can be provided to prevent or block access to such personal information data. For example, in the case of health information or advertisement delivery services, the present technology can be configured to allow users to select to “opt in” or “opt out” of participation in the collection of personal information data during registration for services. In another example, users can select not to provide location information for targeted content delivery services. In yet another example, users can select to not provide precise location information, but permit the transfer of location zone information. 
     In the foregoing specification, specific exemplary embodiments have been described. It will be evident that various modifications may be made to those embodiments without departing from the broader spirit and scope set forth in the following claims. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.