Here my another video showing how to use app inventor and bluetooth communication to interface an arduino board and an android device. This time I am showing how to use the texting function in order to turn the phone into a free GSM shield for arduino.
If you want more general information on interfacing the two, setting it up and want to see more examples - check my earlier instructable ->https://www.instructables.com/id/How-control-arduino-board-using-an-android-phone-a/#intro
Wiring and code is the same as in that example the only difference is the app.
The app can be downloaded here -> https://docs.google.com/file/d/0B_PfPoEotOF8LXpxMi1ucm5RNGs/edit?usp=sharing
The source file (allows you to easily modify the app) -> https://drive.google.com/folderview?id=0B_PfPoEotOF8N2JwT3RSX011SjQ&usp=sharing