All APIs for communicating with the Android system.

The Facebook SDK for Android is the easiest way to integrate your Android app with Facebook's platform. The SDK provides support for Login with Facebook authentication, reading and writing to Facebook APIs and support for UI elements such as pickers and dialogs.

Build Realtime Apps. A powerful API to store and sync data in realtime.

The Google Analytics SDK for Android makes it easy for native Android developers to collect user engagement data from their applications. Developers can then use the Google Analytics reports to measure: The number of active users are using their applications. From where in the world the application is being used. Adoption and usage of specific features. Crashes and exceptions. In-app purchases and transactions. And many other useful metrics... The Google Analytics SDK also gives you the tools to monitor the success of mobile marketing campaigns. Connect user interactions with paid ads, Google Play downloads, and subsequent in-app usage and Ecommerce transactions. Google Analytics provides a powerful platform to measure and optimize all of your application marketing efforts.

Gson is a Java library that can be used to convert Java Objects into their JSON representation. It can also be used to convert a JSON string to an equivalent Java object. Gson can work with arbitrary Java objects including pre-existing objects that you do not have source-code of.

The Google Mobile Ads SDK is the latest generation in Google mobile advertising featuring refined ad formats and streamlined APIs for access to mobile ad networks and advertising solutions. The SDK enables mobile app developers to maximize their monetization on Android, iOS, and Windows Phone 8.

The location APIs make it easy for you to build location-aware applications, without needing to focus on the details of the underlying location technology. They also let you minimize power consumption by using all of the capabilities of the device hardware.

Allow your users explore the world with rich maps provided by Google. Identify locations with custom markers, augment the map data with image overlays, embed one or more maps as fragments, and much more.

Google Play Services give your apps more features to attract users on a wider range of devices. With Google Play services, your app can take advantage of the latest, Google-powered features such as Maps, Google+, and more, with automatic platform updates distributed as an APK through the Google Play store. This makes it faster for your users to receive updates and easier for you to integrate the newest that Google has to offer.

Google Sign-In is a secure authentication system that reduces the burden of login for your users, by enabling them to sign in with their Google Account—the same account they already use with Gmail, Play, Google+, and other Google services. Google Sign-In is also your gateway to connecting with Google’s users and services in a secure manner. You can give your users the opportunity to pay with Google Pay, share with their Google-wide contacts, save a file to Drive, add an event to Calendar, and more. Integrate Google’s user-centric APIs and services inside your app to help your users take action and convert.