I have developed an Android application to control arduino robots via bluetooth .
It's capable of manage direction and speed and can show a measure of distance to the nearest object if it has an ultrasonic sensor to send the information.
The commands that are sent with each key are configurable.
Also include a bluetooth terminal, to send and receive commands to the device, for debugging.
It was thought, at first, to control the Starter Kit V2.0 of Makeblock, but you can control any device, robot ...
If you have any suggestions for improvements or new ideas i'll be happy to hear it.
You can download it here: https://play.google.com/store/apps/details?id=com.mscarceller.makeblockbtcontroller
You can see it working here: Bluetooth Control for MakeBlock V2.0 Starter kit. - YouTube
Thank you very much!