I generated it using MiniSeq, a super simple music sequencing app on Android. Unlike many similar apps out there, it supports saving your session, WAV file generation, and unlike the very cool PocketBand (previously known as uLoops), the program doesn't require a data connection. This means that you can create music anywhere, anytime.
It sure is fun to use, although quite limiting as there's no way to combine loops. Still, as a fun music experimentation tool, it's hard to beat. And I do wonder if it's possible to put together something of value even if it's just 8 notes in a loop.
I've just discovered Plasma Sound, which seems to have quite a bit of promise. It seems fairly powerful, has the ability to record, and doesn't seem to require a network to function. Next time I'm waiting around, I'll have to give that one a try.