Demo app to experiment with Google Play's billing system and app monetization.
The demo shows purchasing of consumable (can be purchased multiple times), non-consumable (can only be purchased once) in-app products and a subscription product. Admob is also integrated where a test ad appears on the bottom of the screen (see static screenshot below).
Requirement to have the app you're looking to add billing to released on the Play Store (internal release is fine..)
Admob test ad seems to work intermittently at best with Ad failed to load error code 0 returned in the console, seems to be a server side issue
Screenshot showing Ad produced by AdMob
Project released under the license GPL V.3.