Android app: Add a bluetooth interface to any Arduino project

Hi,

I made an Android app that allows users to easily exchange data between an Android device and an Arduino project.
It provides a list of "events", such as a button or an integer that can be sent in both directions.
Here are some screenshots of example projects:

This is the link for the app, an example sketch, a tutorial I wrote and Android Code.

I only tested this with my Nexus 4 and with my bluetooth device. So please let me know if it you got it to work. Also, I'm open to improvement suggestions or bugs if you find some.