KLANGLABSR2R2 is an hybrid from a synth and an effect processor, just assign a MIDI track to it to play notes and use an external source (preferably voice) to make the pitch to change.You can achieve interesting sounds with this plug, besides the famous starwars R2-D2 blips you can use it as a synth and use your voice to make weird vibratos.
Specs:
1 main oscillator
2 oscillators connected to a "sample and hold" module, they act as clock modifiers.