This app was mentioned in 3 comments, with an average of 1.33 upvotes
It's not as in depth as other apps, it's more of just a fun one to use, but NodeBeat is pretty cool to mess around with.
It's not a music app like Caustic or any of the others, but I figured it was worth mentioning if you needed an alternative for some inspiration possibly
G-Stomper is an amazing app: http://www.planet-h.com/g-stomper-studio/
Another really fun app is nodebeat https://play.google.com/store/apps/details?id=com.AffinityBlue.NodeBeat&hl=en