Maurizio Giri's Max for Live effects both rely on granular synthesis to produce results ranging from subtle to overwhelming. The latest, Grain Reverser, reverses audio input and applies granular effects like transposition and duration variation, in addition to filtering. The results, as you can see and hear in the video below, can enhance a sound, or get quite psychedelic:
Granular Max for Live effects from Maurizio Giri
Maurizio's previous Max for Live effect, Granular Mirror Maze, is a delay/reverb with granular features and a similarly wide range of uses, from basic echoes to noisy feedback trails: