I see that projectM for android is closed source (cause your charging money for it) and I've been looking over the internet trying to find a way to record audio output like projectM does and I can't for the life of me find out how to do it without using private APIs. How did you do it? Perhaps just a point in the right direction?
ah, nm. I think I found it. Are you using http://developer.android.com/reference/android/media/audiofx/Visualizer.html