Here's a little demo of an arpeggiator for the Volca Keys. It uses cpwitz/midi/arpeggiator object (thanks @cpwitz ! )
Sorry about the shitty audio, it is coming out of my headphones and recorded with my cellphone.
The knobs do, from left to right:
-Direction (R is random and O is order)
-Probability (the higher the more notes are played) It uses phi/prob/%prob object (thanks @philoop !)