I've just got a Galaxy Note 2 so with the big screen I'm looking to get some Android music Apps (was too small and fiddly on my older phone)
These are a couple of decent free things I've been using:
My Piano: (Free) Simple virtual piano with 11 instruments and 7 effects, recordable. The best feature is the sampler- record any sound and you can instantly muck about with playing it as different notes/adding effects.
https://play.google.com/store/apps/deta ... iano&hl=en
Etherphone: (Free) Theremin app.
https://play.google.com/store/search?q=etherophone
Synprez FM Synthesizer: (Free) Still getting to grips with this, it seems good if a bit fiddly and not too user friendly.
https://play.google.com/store/apps/deta ... z.fm&hl=en
Groove Mixer (Free): Drum machine/sequencer, good for quickly putting together beats on a grid but doesn't have much else to it so you need to have the samples exactly as you want them before using it.
http://groovemixer.com/
Electrum Drum: (Free demo, £2.61 full) Drum machine that looks like an 808- not such an intuative layout for putting together multiple parts as groove mixer but you can add a few effects to samples.(I can't really see the point of making the layout the same as the hardware was when a grid layout works much better for touchscreens, and this is from someone that had an MC303 and 505)
https://play.google.com/store/apps/deta ... rums&hl=en
Caustic: (Free demo, £5.29 full) Just bought the full version so still getting used to it, possibly the best DAW type android app. Well worth a go on the free version as it's the same thing but without ability to save files.
.....Although Ive been mucking about on SPC (Free demo, £5 full) and that seems to have a few features that Caustic doesn't- it's quicker and better for mucking about with samples, can run samples through more effects and has features for cutting and reversing samples you've directly just recorded etc. I think this might be the app that gets most use from me while on the go by cutting and looping files on the phone because proper production (more like Caustic) is the sort of thing I save for doing at home on a much better system like Logic.