PolyBud is a multitrack polyrhythmic AUv3 MIDI sequencer. You can add multiple note or MIDI CC tracks to the each pattern. The note tracks has the note, velocity, gate, ratchet, probability and randomisation modes. You can set different step lengths to the each mode which would introduce polyrhythmic variations immediately.
Another great feature is the each track can run in a different rate which is great for creating unique polyrhythmic sequences. Also, you can assign different MIDI channels to the each track so that you can control multiple synths within a single PolyBud pattern.
The MIDI CC tracks is great for modulating the synth parameters. You can introduce polyrhythmic modulations by setting the different step lengths and different rates to your MIDI CC tracks. Also, you can set a ramp value for smoothing up the CC value changes per step. If you set the ramp value to 0% then you can have the classic sample and hold modulation.
PolyBud is a MIDI app and it don't produce any sound of its own. You need to route PolyBud's MIDI out to your audio apps in order to run PolyBud. For the AUv3 plugin, you need an AUv3 host app such as AUM, Cubase, NanoStudio, ZenBeats, BeatMaker, apeMatrix etc.