Muckraker

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. Map external controllers to the effect controls with learnable MIDI CC. Multitask in split screen or slide-over mode on supported iOS 9+ iPads.

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. (You can also now switch off the automatic muting in the iOS Settings.)

(Note also that Muckraker does *not* provide an Audio Unit extension. Porting the underlying tech to the AUv3 environment is sadly not practical. I know this is disappointing, but Muckraker and its sibling apps are stuck in their historical moment; when IAA goes away, so will they. Perhaps something else will come along to take their place...)