The following services and features help developers to add YouTube functionality to their Android apps.
YouTube Android Player API
The YouTube Android Player API lets you incorporate video playback functionality into your Android applications. The API defines methods for loading and playing YouTube videos (and playlists) and for customizing and controlling the video playback experience.
Android Live Streaming
The YouTube Mobile Live deep link enables Android applications to initiate a YouTube live stream directly from a mobile device. An app only needs to provide an entry point, such as a button that the user can click, that starts the Mobile Live flow via the Android Intent mechanism.