The Linux Kernel

Linux Kernel is an open-source component of Linux OS that controls functions and manages resources between devices and processes. The Kernel resides in the middle, between the CPU and users, managing apps and processes, memory, and service calls.

Hardware Abstraction Layer (HAL)

The hardware abstraction layer is a software subsystem that holds the library modules that communicate through interfaces with specific devices’ hardware components, such as audio, camera, sensors, and Bluetooth.

Android Runtime

Android Runtime (ART) is the default runtime for apps and system services that translates dex bytecode format files into native instructions. Its most relevant features are ahead-of-time compilation (AOT), garbage collection (GC), debugging options, and diagnostic and crash reports.

Android Java Framework

Android’s OS features are available through Java APIs for creating apps that facilitate modularity and access to resources and provide a view system and layout to structure the app’s user interface (UI), activities and notification management, and implementation of content providers.
Native C and C++ libraries’ functionalities are exposed to apps through APIs supported in the Java Framework.
The Android platform has system apps with functionality and capabilities accessed from the app being developed.

Learn more about Android’s architecture

Modern app architectures prioritize user-driven interfaces and utilize modular app components, which can operate independently. This is crucial as apps may need to close processes or terminate interactions in response to system or user conditions to free up resources.
App design considers the principle of separation of concerns, ensuring that processes, tasks, activities, and interactions are logically organized. User perspectives and behavior are key considerations, particularly on the sequence of activities (activity stack) and their lifecycles. This focus ensures efficient processing and an optimal application model.

Android components have independent interaction points between system and app activities, fragments, services, events (broadcast receivers), and contents (data). Components are subclasses, and some are implemented through APIs that integrate processes within the app when they should be running or working in conjunction with other apps.
Other apps can start app components to perform instances processed in the app that perform the activity with specific permissions. The Android system receives a message specifically intended to activate the needed component. Components are triggered and activated by intent or request methods. These components are declared in the manifest file and reside at the root of the directory.

• App Manifest. The app manifest provides essential information on the app components, activities, properties, and capabilities. It also describes permissions, package attributes (application ID), XLM elements, intent filter declarations (describing capabilities), API level, API libraries, icon and label attributes, hardware and software features needed by the app compatibility of devices, and minimum version. A manifest file is created, and elements are added during the app development.

• App Resources. App resources (besides the code) such as images, files, and other assets are defined with XML files and unique integer IDs used to insert into the interface (UI) and easily referred to when configuring other devices.

Android apps are designed to solve user problems considering specific contexts and situations. Therefore, the approach to developing the app architectures can vary.

Android Studio

Android Studio is Google’s official integrated development environment (IDE) for coding Android apps that are flexible, fast, and fully featured, supporting a productive app development process. It has a view system organized by modules, code files, and non-code resource files. In addition, the main window is versatile, having customized options to adapt toolbars, tool windows, and keyboard shortcuts.

Android Studio supports most version control systems (VCSs), with a display menu to choose the desired VCS system, create repositories, import files, and select integration options. Developers download Android Studio, and a project is created. The code is built with the help of specialized tools to create user interfaces (UI) and build customized variants (for different versions) and Android Application Packages (APKs).

Android Emulator

Creating an Android virtual device (AVD) allows running the app in the app emulator to test the application on many devices without physically having them. Code can be tested on Android phones, Wear OS, tablets, and TV devices.

Debugging and optimizing performance follow in refining a version of the app for release or publishing.

Jetpack Compose. Jetpack is a toolkit built on Kotlin to build high-quality native user interfaces (UI) across Android, offering Kotlin APIs fully interoperable with Java. It accelerates development and eliminates boilerplate code. Jetpack libraries are comprised of the Android namespace and have backward compatibility. This replaces the Support Library with classes and artifacts mapped to Androidx that facilitate migration to AndroidX.

A Jetpack Compose app project is created from the Android Studio with supported new project templates. For more information about Jetpack, check out the Jetpack Compose Basics tutorial.

Android app developers ensure that apps are continuously updated and compatible with new Android version releases to adapt and support platform changes. In addition, developers review system behavior changes, run tests, adapt code, and resolve issues.

Android 13 introduces several new features and improvements to enhance user experience (UX). For example, with better error reporting in Keystore and Key Mint, developers can expect more detailed and accurate error indicators when generating keys. In addition, Android 13 builds on the tablet optimizations introduced in Android 12, including optimizations for the system UI, improved compatibility modes, and better multitasking. This makes it important for developers to test their apps on tablets and other large-screen devices to ensure they look their best.

Another major addition in Android 13 is the support for High Dynamic Range (HDR) video capture through the Camera2 APIs. HDR video capture allows users to preview and record video content with a wider range of colors and an increased dynamic range of the luminance component. In addition, spatial audio and anticipatory audio routing have also been introduced to make media content more realistic for users.

Furthermore, Android 13 includes extended support for SocketOptions and updates to java.util.concurrent to OpenJDK 11 API using VarHandle internally. For a full list of features and improvements, refer to the official Android 13 features page.

Bluetooth LE Audio

Bluetooth LE Audio is a wireless audio technology that replaces Bluetooth Classic, allowing users to share, broadcast, and subscribe to public broadcasts for information, entertainment, and accessibility. Android 13 includes built-in support for LE Audio, offering high-fidelity audio without compromising battery life.

The Android 14 release is coming in the months ahead. It is currently in its beta version, which is available for development.

Krasamo developers are working on updating Android apps and making them ready for Android 14, trying new APIs and features, and testing changes to support app behavior properly.

Android 14 improves developer productivity with the following new features:

Internationalization

• Android 14 offers an automated approach for supporting per-app language preferences, dynamic updates for an app’s localeConfig, and improved visibility of app languages for input method editors (IMEs).

• Grammatical Inflection API lets you add support for grammatical gender in gendered languages without refactoring your app, improving user engagement by providing a more personalized and natural-sounding user experience.

• Regional preferences allow users to personalize temperature, day of the week, and numbering systems. In addition, they include new Android Settings, menus for these preferences, APIs, and intents that grant apps read access to adjust how they display information.

Accessibility

• The Android system’s non-linear font scaling up to 200% provides low-vision users with additional accessibility options that align with WCAG by preserving the proportional hierarchy between elements of different sizes and mitigating issues with linear text scaling.

UX Experience

• Android 14 enhances the system share sheet by enabling custom actions for different apps. It also improves the ranking of direct share targets by utilizing more app signals. The most useful signal for ranking is reported through the pushDynamicShortcut function, which generates a corresponding shortcut when a user sends a message to a contact.

• It introduces the requestUserPreapproval() method, which enables app stores to request user approval before initiating the install session. With this method, the system can defer downloading any APKs until after the user has approved the installation, allowing the app to download and install in the background without interrupting the user. This helps improve user experience and enhances the security of the installation process.

• The setRequestUpdateOwnership() method allows installers to claim responsibility for future updates to an app, enabling update ownership enforcement to ensure users receive updates only from the expected app store, with other installers requiring explicit user approval to install updates.

• The InstallConstraints API provides a way for installers to ensure app updates happen at less-disruptive times by calling the commitSessionAfterInstallConstraintsAreMet() method to commit updates only when the user is not interacting with the app.

• The setDontKillApp() method enables app stores to install features while using the app without killing running processes, and PackageInstaller API has supported splits since API level 22.

• Introduction of a screenshot detection API that allows apps to register callbacks per-activity basis and notify the user when they take a screenshot while that activity is visible.

Graphic

• Developers can now query paths to retrieve data and interpolate them using PathIterator objects and the interpolate() method, respectively, while the Jetpack graphics-path library provides similar APIs for previous versions of Android.

Core Functionality

• Improved support for OpenJDK 17 updates, including new language features and library updates for app and platform developers.

TV has become the main gateway to the connected home. OTT services (over-the-top) or TV provided over the internet has become mainstream, with subscriptions booming and consumers streaming content and music, playing games, etc.

The Android TV Platform is among the top smart TV OEMS, TV operators, streaming content providers, and TV apps.

Voice technologies have advanced and are giving users the power to control their TVs and other smart devices from their TVs. Google Assistant is another powerful tool—built into Android TVs—that enables users to connect with other technologies and control their on-demand content.

A simplified content user experience and ecosystem integration have created the right timing to initiate an Android app development project to work with Android TV.

Designers can now build TV apps using the same structure as for phones or tablets, based on their experience with Android or by extending existing apps to run on TV devices and adapting the user interaction design model for new layouts and navigation.

Android 13 for TV is the latest version of Android TV OS that offers enhanced performance and accessibility to enable developers to create compelling apps for the next generation of TVs.

• New APIs help developers deliver high-quality experiences on different device types.
• AudioManager API improvements provide for optimal format selection and playback.
• Users can change the default resolution and refresh rate for more reliable playback.
• HDMI state changes surfaced to the MediaSession lifecycle for saving power and pausing content.
• InputDevice API supports different keyboard layouts and physical key locations for game developers.
• Newly created audio descriptions API in AccessibilityManager offer automatic user preference alignment.
• Android TV OS developer site has more details on additional features.
• Available on ADT-3 and Android TV emulator for testing on Google TV or standard Android TV interface.