Audiobus: Use your music apps together.
Audiobus is the app that makes the rest of your setup better.
THESE ARE BROKEN - 3 Free New AUv3 Effects from Cristiano Piatti
FuzzBox: Cubic exponent function based distortion effect. 82.9MB.
WaverSine: Sine wave convolution based distortion effect. 103.6MB.
ModulatorSquare: Square wave amplitude modulator effect (aka tremolo). 117MB.
Modelled on a physical based algorithm and low level coding for state of the art performance and sound quality.
Audio unit AuV3 plugin technology support (Metal API in full screen mode).
I don't have space for them, so didn't try them yet. Anybody else?