Okio is a new library that complements java.io and java.nio to make it much easier to access, store, and process your data.

Volley is an HTTP library that makes networking for Android apps easier and most importantly, faster.

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

ZXing (pronounced "zebra crossing") is an open-source, multi-format 1D/2D barcode image processing library implemented in Java, with ports to other languages. Our focus is on using the built-in camera on mobile phones to scan and decode barcodes on the device, without communicating with a server.

All APIs for communicating with the Android system.

DoubleClick is the ad technology foundation to create, transact, and manage digital advertising for the world's buyers, creators and sellers. Available for iOS and Android

An image loading and caching library for Android focused on smooth scrolling

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.

A service for developers that allows users to share the app with people that they know.

Google Play services offers a standard authorization flow for all Google APIs and all components of Google Play services. In addition, you can leverage the authorization portion of the Google Play services SDK to gain authorization to services that are not yet supported in the Google Play services platform by using the access token to manually make API requests or using a client library provided by the service provider.