Topeka - Android
When Google launched Material Design, they needed to show real-world usage of the new design and released Topeka a web version of Material Design. Today, they’ve launched Topeka for Android to show how Material Design principles should be applied on a mobile app platform.

As with the previous web app, Topeka for Android is open source – it’s designed as a teaching aid after all. The app shows how all the usual elements associated with Material Design such as Floating Action Buttons (FAB) and all those wonderful animations and transitions.

As with their previous web app, Google has made the Topeka Web App available on their GitHub page. On the GitHub page you should find all the examples and information on Material Design implementation that you could need.

Source: Android Developers.