This is a pretty neat app. Just played around with it some. I will say, the timing is pretty rough on most of the songs, but I like the idea of using this just to get an idea of what chords the song has then doing it on my own from there. The app isn't really timed well enough to give you the full picture, but just a snapshot of idea of the chords in the song.

This looks wonderful for people learning to play musical instruments