First version of a Tic-Tac-Toe Android app

You can play Tic-Tac-Toe against your Android smartphone. You can find the APK for the installation in the bin folder. The app requires no extra permissions. I am using this app in order to learn more about Android app development, sort of as a playground.

Update: Fixed bug regarding the center button, added a few extra cases I haven't considered before

To be added: A better UI, animations, different playing modes. Suggestions are welcome