# IOS 9

iOS 9 is the ninth major release of the iOS mobile operating system developed by Apple Inc., being the successor to iOS 8. It was announced at the company's Worldwide Developers Conference on June 8, 2015, and was released on September 16, 2015. It was succeeded by iOS 10 on September 13, 2016.
iOS 9 incorporated many feature updates to built-in apps. Most notably, Notes received the ability to draw sketches with different tools, image insertion, prominent visual appearance for website links and map locations, and advanced list formatting; an all-new Apple News app aggregates articles from different sources; and Apple Maps received mass transit support, although in a limited number of locations at launch. Major new system updates include proactivity, where Siri and advanced search are combined to make the operating system more contextually aware of information (such as time and location), and can provide the user with information ahead of time. For searching, the proactive intelligence can display instant results in a widget-like format, including weather, sports, news, and more. iOS 9 also added multiple forms of multitasking to the iPad. In iOS 9.3, Apple added a Night Shift mode that changes the color of the device's display to a warmer, less "blue light" containing shade, to reduce any negative eye health effects on users' circadian rhythms. Additionally, iOS 9 brought new user experience functions, including Quick Actions, and Peek and Pop, based on the touch-sensitive display technology in the iPhone 6s. Quick Actions are shortcuts on home screen app icons. Users can preview ("Peek") at content without moving away from the current screen before they enter ("Pop") the previewed content into full view.
Reception of iOS 9 was positive. Critics praised proactivity and Siri for making the Notification Center a central location for all information, and the potential for future updates to improve the functionality. The new multitasking features for the iPad were complimented, as were drawing and photo insertion in the Notes app. However, Apple News was criticized for a low number of decent-looking articles, and Apple Maps was criticized for the limited geographical availability of mass transit support.
Five days after release, Apple announced that iOS 9 had been installed on more than 50% of "active" iOS devices, which Apple described as the "fastest adoption rate ever for a new operating system".
iOS 9 is the final version of iOS to feature the classic slide-to-unlock gesture. With the release of iOS 10, Apple introduced the Today view, which was accessed on the lock screen by swiping to the right. Apple removed slide-to-unlock in iOS 10 because it would create confusion when users were trying to unlock their phone by sliding the screen, but instead of unlocking the phone, it took them to the new Today view. iOS 9 is the final version of iOS compatible with devices with the 30-pin dock connector, including the iPhone 4s, iPad 2, and iPad (3rd generation). It is also the final version of iOS that supports the iPad Mini (1st generation) and the last 32-bit iPod Touch, the iPod Touch (5th generation). iOS 9's successor, iOS 10, drops support for devices with A5 or A5X chips.

## Overview

iOS 9 was introduced at the Apple Worldwide Developers Conference on June 8, 2015, with the first beta version made available to registered developers after the keynote, and a public beta made available in July.
This marked the first time that the general public had been able to test new versions of iOS before official release, with Eddy Cue, Apple's Senior Vice President of Internet Software and Services, telling Fast Company that the public beta program was started "because of Maps", referring to the company's Apple Maps launch that had significant issues in its early days.
iOS 9 was officially released on September 16, 2015.

## System features
### 3D Touch

On the iPhone 6s and iPhone 6s Plus, a touch-sensitive display feature called 3D Touch is incorporated into iOS 9. It is similar to Force Touch, which can be found on the trackpad of some Apple MacBook computers. Quick Actions and shortcuts are added to apps that support the 3D Touch feature and are triggered by pressing slightly harder on the app icon. It also introduces actions known as Peek and Pop, which lets users firmly hold to preview ("Peek") any kind of content in a hovering window, before they optionally apply more pressure to enter ("Pop") the content into full view.
The taptic engine in the iPhone 6S provides haptic feedback each time users press the screen harder.

### Battery

iOS 9 comes with two important battery-saving updates. When a phone has been placed face-down, the screen will not light up upon receiving notifications. Apple has also added Low Power Mode, which modifies the amount of energy dedicated to background services and animations. For example, background app refresh and push email are paused during Low Power Mode. When a phone reaches 20% battery level, users are automatically prompted to turn on Low Power Mode, which changes the color of the battery icon in the top row status bar on the screen to yellow. When the battery goes higher than the 80% level, Low Power Mode automatically turns back off.

### Design

San Francisco, a new system font, replaced Helvetica Neue as the system typeface of iOS.
iOS 9 added a new battery widget to the Notification Center that displays the battery life and charging status of any connected Bluetooth device.
When the shift button is inactive, lowercase letters are displayed on the keyboard, instead of the all-caps representation on previous iOS versions.

### Installation

iOS 9 is a smaller update than iOS 8, requiring just 1.3 GB of space, compared to 4.58 GB for iOS 8. Additionally, iOS 9 includes an option to temporarily delete apps to allow the update to install. Once the update has been installed, the apps will be automatically reinstalled from the App Store. iOS 9 also features "app thinning" functionality, whereby only the necessary assets needed to run apps on each individual device is downloaded rather than the entire app, potentially saving space. For example, with the new app thinning technology, when a user downloads a new app onto their new iPhone 6S, the download would only include the images and data that are required on that device, so that no space is required for the images and data that would not be used on the device.

### Multitasking

For the first time, iOS 9 adds a number of features to the iPad to improve productivity. These include Slide Over, Split Screen, and Picture in Picture, for enhanced multitasking, similar to the experience found on OS X El Capitan. Slide Over allows the user to pull in a second app with a swipe from the right edge of the display. This app takes up 1/3 of the screen and sticks to the right side of the screen, while interactivity within the full-screen app is disabled while left inactive in the background. The feature allows users to perform quick tasks and then dismiss the app again.
If the user taps on the handle next to the Slide Over window or extends the window further towards the left of the screen, the user enters Split Screen, which allows them to interact with two apps simultaneously side-by-side in a 50/50 split. Users can also switch to another app in either Slide Over mode or Split Screen view by pulling down on the handle on top of either app and selecting another app from the list to replace the existing one.
Picture in Picture mode allows users to minimize FaceTime calls or supported videos to a smaller window and continue watching them while doing other tasks on the iPad.
The Split Screen multitasking feature is only available for iPad Air 2, iPad mini 4, and iPad Pro, while the Slide Over and Picture in Picture features are available on the iPad Air, iPad Air 2, iPad mini 2 and newer, and the iPad Pro.
When banner notifications are tapped, causing another app to open, a back button at the top-left corner of the screen has been added, bringing the user back to the previous app.
On iPhone, iOS 9 changed appearance of its app switcher from side-by-side view in iOS 8 to card-like view.

### Night Shift

Night Shift is a display mode introduced in iOS 9.3. The mode shifts the colors of the device's display to be warmer, similar to F.lux, a popular program for Microsoft Windows and Apple macOS computers. When enabled, it uses the device's clock and geographic location to determine when to turn the feature on or off. Optionally, the user can set a manual schedule, or not have a schedule at all. For ease of access, there is a new Night Shift toggle in the Control Center. The settings for Night Shift are located under "Display and Brightness" in the Settings app, and on top of enabling the feature and setting a schedule, the user can also set the warmth of the display.
Despite being introduced in iOS 9.3 in March 2016, it wasn't possible to use Night Shift and Low Power Mode simultaneously until the release of iOS 9.3.2 two months later. Night Shift requires a 64-bit processor only found in the Apple A7 or newer chips, which means older iOS devices, including the iPhone 4s, iPhone 5, iPhone 5c, iPad 2, iPad 3, iPad 4, first-generation iPad Mini, and 5th generation iPod Touch, do not receive Night Shift mode.

### Performance

iOS 9 includes performance and speed improvements thanks to the expanded use of the Metal API. Metal was introduced in iOS 8 and was previously limited to game developers. In iOS 9, the use of Metal is expanded to let it handle many of the core user interface elements and graphics.

### Proactivity

Intelligence is one of the main features in iOS 9, consisting of the newly integrated Siri and Search (previously known as Spotlight), as well as "proactivity" throughout the operating system. iOS is now more aware of contextual information (such as time and location), and proactively provides the user with what they may need in advance to save them time and effort. When typing, Search has also been improved to display instant answers in an at-a-glance, widget-like format, similar to that provided in the Siri interface. Search can display current weather, sports scores, news, and more. The Search screen with proactive suggestions can be accessed either by pulling down the notifications window, in the Safari web browser through the search bar, and to the left on the home screen.
The intelligence also extends into apps. For instance, in Mail, events can be automatically added to Calendar if details are found in the message content, and likely additional recipients are suggested during message composition. Siri is also aware of what is currently on screen when it is engaged by holding down the home button.

### Security

iOS 9 introduces multiple security enhancements. It introduces a 6-digit passcode as a default, an extra two digits over the previous 4-digit default, as well as support for two-factor authentication. 6-digit passcodes were much more secure because there were now 1 million possible passcode combinations compared to just 10,000 for 4-digit passcodes.
The original iOS 9 release in September 2015 fixed a security issue in previous iOS versions, in which a "flaw allowed anyone within range of an AirDrop user to install malware on a target device and tweak iOS settings so the exploit would still work if the victim rejected an incoming AirDrop file".

### Settings

The Settings app in iOS 9 includes a new search bar that makes it easier to find settings and options. The user also has options to have notifications be grouped by which app they came from, and the ability to turn on or off Shake to Undo.

### Other changes

On iPad, a two-finger drag on the keyboard moves the cursor freely like a traditional trackpad, making positioning the cursor and selecting text easier. The keyboard-to-trackpad feature is also extended to iPhone 6S and 6S Plus, in which users can 3D Touch (force press) the keyboard to enable the trackpad. Also on the iPad, a shortcut bar has been added for cut, copy, paste, undo, and redo functions, and folders display 16 apps per page in a 4-by-4 arrangement, compared to 9 on the iPhone, allowing for an increased total of 240 apps in a single folder.
iOS 9 introduced Wi-Fi Assist, a feature (enabled by default) that automatically switches the phone to cellular data when the Wi-Fi connection is spotty.
Whenever the user is presented with flight information, the user can click on a link to view a preview for that flight.

## App features
### iBooks

With iOS 9.3 and later, PDFs saved to the iBooks application via Safari or iTunes can be synced with iCloud.

### iCloud

iOS 9 has a setting that enables an iCloud Drive app on the home screen. iCloud Drive lets the user save and browse files and folders in iCloud.

### Health

The Health app, introduced in iOS 8, has received landscape mode on iPhone. It also added support for reproductive health, UV exposure, water intake and sedentary state data types.
In iOS 9.3, it also tracks sleep, exercise, and weight from the Apple Watch.

### Messages

Messages now allows the user to search for text and have that text be highlighted (and scrolled).

### Maps

Apple Maps adds support for transit directions in Baltimore, Berlin, Chicago, London, Los Angeles, Mexico City, New York City, Paris, Philadelphia, San Francisco, Toronto, and Washington, D.C., along with "over 300 locations in China."
The Maps app now also has enhanced location details, including a Nearby feature that recommends shops, restaurants and places to drink in close proximity to the user. For places serving food, users can specify exactly what type of food they want.

### News

iOS 9 includes a new Apple News app (replacing the Newsstand app), which aggregates news from different sources in a similar style as Flipboard. The app features a "mobile-formatted layout that loads quickly and has informative animations and full-bleed images". Additionally, News supports RSS feeds from the Safari web browser. At launch, the News app was only available in the United States, but it was expanded to the United Kingdom and Australia with the iOS 9.1 update.
In March 2016, Apple opened the News platform to all news agencies, including independent bloggers.