What's a good Android app for stripping the vocals out of a song so I can practice my guitar licks over it?

Alright, so I needed something that could pull the vocals out of some old tracks so I could finally nail that Clapton solo. Tried a few apps, and most were about as useful as a screen door on a submarine. Then I found Moises. The tutorial is a waste of time, honestly. But once I messed around with it for a bit, I figured out how to isolate the tracks. It's actually pretty slick. I can kill the vocals, slow the song down without messing up the pitch, and finally learn that solo. Battery life takes a hit, especially when you're messing with the settings, but hey, gotta expect that. It's not built like a brick house, but it gets the job done, even with my gloves on sometimes. Rain doesn't stop it either. So yeah, Moises. It ain't perfect, but it's the best I've found for this kind of thing.