MeggySeq is a pattern-based drum machine sequencer. It has 8 patterns of 16 steps each and each step can play one of 8 samples (the colors are hard to tell apart on the video).
MeggySeq is currently in development.
Next steps: Saving patterns to the eeprom, sending MIDI (currently it just sends single characters over serial to the WaveShield) and possibly syncing to external clock sources. Or, you know, changing the tempo at all.