Great article from Pro Audio Files with M4L device recommendations and descriptions.
The DHM 89 pitch-shifting delay unit was released in 1979 by the French manufacturer Publison. PitchLoop89 takes its cues from the hardware, preserving some original limitations for creative reasons, while making some contemporary enhancements for sound control, versatility and performability. It’s free.
This free Ableton Live rack is a combination of Pre-Gain Staging, Waveshaping saturation, Overdrive with adjustable center frequency, Bit Crushing tuned to noise and less tone loss, stereo distortion, and filtering with cabinet.