A GuitarPro-like app for Android that works with your actual guitar
Understanding chords and musical notes from a recording is a tough job. However, it is really appealing to just grab your guitar and play without connecting it to any special device that will parse the vibrations and correctly understand everything.
This Android app does exactly the opposite: it uses the smartphone microphone and parses the chords and notes from the audio alone.
As a result, it can challenge you to play a song and then evaluate the correctness with which you played it.