From the App Store: Muckraker is an abstract audio distortion effect to annihilate your sound. Add a gentle fuzz to your guitar or blast your synth harmonies into brutal white noise. Use with the built-in mic or an external instrument interface, or connect to other compatible music apps such as GarageBand via Inter-App Audio or Audiobus.
Easy does it: a little muckraking goes a long way!
Note: Muckraker starts out muted for a good reason. It can feedback like — well, some very feedbacky thing. If you don’t hear anything, check the mute button.