Android KitKat

Android KitKatis the codename for the eleventhAndroidmobile operating system, representing release version 4.4. Unveiled on September 3, 2013, KitKat focused primarily on optimizing the operating system for improved performance on entry-level devices with limited resources. As of October 2022,1.39% of Android devices run KitKat.On July 24, 2023, Google announced thatGoogle Play Serviceswould no longer support KitKat in August of that year.The first phone with Android KitKat was theNexus 5.
Android 4.4 "KitKat" was officially announced on September 3, 2013. The release was internally codenamed "Key lime pie"; but John Lagerling, director of Android global partnerships, and his team, decided to drop the name, arguing that "very few people actually know the taste of a key lime pie". Aiming for a codename that was "fun and unexpected", his team pursued the possibility of naming the release "KitKat" instead. Lagerling phoned a representative ofNestlé, who owns theKit Katbrand and produces the confectionery (outside theUnited States, where it is produced byThe Hershey Companyunder license), and quickly reached a preliminary deal for a promotional collaboration between the two companies, later finalized in a meeting atMobile World Congressin February 2013. The partnership was not revealed publicly, or even to other Google employees and Android developers (who otherwise continued to internally refer to the OS as "KLP"), until its official announcement in September.
As part of the promotional efforts, Kit Kat bars in the shape of theAndroid robot logowere produced, while Hershey ran a contest in the United States with prizes ofNexus 7tablets andGoogle Play Storecredit.
TheNexus 5, developed byLG Electronics, was unveiled on September 30, 2013, as the launch device for KitKat.
Up to October 2017, Android 4.4 was still supported with security patches by Google for thesource code.
Continuing on from the focus on improving visual performance and responsiveness onAndroid 4.1 "Jelly Bean", the main objective of Android 4.4 was to optimize the platform for better performance on low-end devices, without compromising its overall capabilities and functionality. The initiative was codenamed "Project Svelte", which Android head of engineering Dave Burke joked was aweight lossplan after Jelly Bean's "Project Butter" added "weight" to the OS.To simulate lower-spec devices, Android developers usedNexus 4devicesunderclockedto run at a reduced CPU speed with only a single core active, 512 MB memory, and at 960×540 display resolution—specifications meant to represent a common low-end Android device.
A development tool known as ProcStats was developed in order to analyze the memory usage of apps over time, especially those that run background services. This data was used to optimize and decouple Google apps and services found to be inefficient, thus helping to reduce the overall memory usage of Android. Additionally, 4.4 was designed to be more aggressive in managing memory, helping to guard against apps wasting too much memory.
The overall interface of KitKat furtherdownplaysthe "Holo" interface appearance introduced on4.0, replacing remaining instances of blue accenting with greys and white (such as the status bar icons), and getting rid of theWi-Fiupstream and downstream traffic indicators (triangles pointing up and down), though they can still be seen in the quick control center menu.
The Wi-Fi icon colour when only a connection to an access point with no Internet access has been established has changed from grey to orange.
The appearance may deviate in custom vendor distributions such asTouchWiz.
Apps may trigger a translucent status and navigation bar appearance, or trigger a full screen mode ("Immersive mode") to hide them entirely. The launcher also received a refreshed appearance, with the implementation of the translucent navigation bars, and the replacement of the black backdrop in the application drawer with a translucent backdrop.Additionally, action overflow menu buttons in apps are always visible, even on devices with the deprecated "Menu" navigation key.In the Settings menu, users can now specify a default Home (launcher) andtext messagingapp.
On stock devices, the Messaging and Movie Studio apps were removed; the former was replaced byGoogle Hangouts, which supportedSMS. The AOSP Gallery app was also deprecated in favor ofGoogle+ Photos.
A newruntime environmentknown as theAndroid Runtime(ART), intended to replace theDalvik virtual machine, was introduced as atechnology previewin KitKat.ART is a cross-platform runtime which supports thex86,ARM, andMIPSarchitectures in both32-bitand64-bitenvironments. Unlike Dalvik, which usesjust-in-time compilation(JIT), ART compiles appsupon installation, which are then run exclusively from the compiled version from then on. This technique removes the processing overhead associated with the JIT process, improving system performance.
Devices with 512 MB of RAM or less report as "low RAM" devices. Using an API, apps may detect low RAM devices and modify their functionality accordingly. KitKat also supportszram.WebView components were updated to utilize a version of theGoogle Chromerendering engine.A new Storage Access Framework API allows apps to retrieve files in a consistent manner; as part of the framework, a new system file picker (branded as "Documents") allows users to access files from various sources (including those exposed by apps, such as online storage services).
A public API was introduced for creating and managingtext messagingclients.Sensor batching, step detection and counter APIs were also added.KitKat supportshost card emulationfornear-field communications, which allows apps to emulate asmart cardfor activities such asmobile payments.