iPhone app that displays waveform?

Does anyone know of a media player that displays a waveform for the track your listening to? I'm trying to practice some new songs that I had my guitar player record the guitar parts for, and the riffs are kind of complex so sometimes its hard for me to know when the changes are coming. If I could view the waveform while the song is playing, I would know when the changes are coming.

Anyway, does anyone know of a way I can get my iPhone to display a waveform, or an app that will do this?


Thanks

If you post it on soundcloud, if you want it for yourself just set the track to private.

I think that just writing down some notes on when the changes are would be a lot more efficient though. eg "verse 1-1bar" "chorus1-2 meters" ect.