Frobulator (universal) arrives
Frobulator is an experimental stereo modulated filter and delay effect. A combination of time and frequency domain processing gives it a different sound to a normal echo box. The special "FAIL" mode adds chaotic variations driven by an iterative map -- perfect for those times when your music is just too harmonious and listenable.
Apply Frobulator to live audio input, or connect with other music apps like GarageBand via Inter-App Audio or Audiobus. Frobulator supports Audiobus state saving and has IAA host transport controls.
NB: to avoid some nasty feedback, Frobulator is muted by default if you're using the built-in microphone and speakers on your iOS device. If you aren't getting any sound out, try pressing the mute button.
Frobulator is free on the app store: