FretTrainer 1.0

the author of this app says:

This guitar can be played right on your device!

This application is designed to help you get acquainted with guitar chords. With each key that you tap a note comes out. You can look at the tips that are provided with the application for reading and playing notes. If you tap on the wrong key, the device will tell you.

While testing it, I had a blast making tunes.