waveform
waveform is a digital video synthesiser built for iOS rendering to an OpenGL ES view. it provides UI to choose from a set of different types of waveform against the red, green and blue channels of the output image as well as a music reaction toggle that randomises selected options when it hears a beat

additionally an interface for blending videos / photos from your image gallery allows for some beautiful results especially when used in conjunction with glitchy vertex mangling