I want to study specific API's and technologies for the Android platform. To achieve that i'm planning to build an application that will allow people to share promotion prices on beer, wine, vodka and any booze at all and their places using the google place picker API. It will also show to the user the avaliable promotions near him. It can be extended to regular products but my focus right now is on technologies i'm going to use :)

Google Place Picker
MVP - Model View Presenter Architecture
Dagger 2 - Dependency Injection
Butter Knife - View Injection
Robolectric - Tests
Mockito
Retrofit - Rest communication
Retrolambda
RxAndroid

I want to try it out the Play! Framework. It's build on top of Akka which makes it high scalable and it's restful.

Play! Framework
Java or Scala - I think i will go with scala
Angular JS
Bootstrap