This article at Intelligent Machinery talks about how to use text editors and image editors to glitch out audio in different ways.
The same methods can of course be used in many image/text editors on Android to.
I did also have fun opening up non audio files in the SunVox sampler and got some interesting results out of it.
Yes it is almost going to be noise in one way or another but it can be useful and good for experimentation like slowing it down for example...
To read and listen: