Djam.  Used the Figure app from Propellerhead for the drum & bass.  Used Amplitube for guitar.  Quick fun...all improv.  I may go back and tweak the drums.  Using Audiobus, it's easy to record from Figure into Amplitube.  I looped the drums and recorded about 5 minutes.  Then recorded the bass next to the drums.  With the multitrack, create several drum patterns in Figure, recording each one to it's own track.  Gotta love Audiobus!