i've recently downloaded zxtune on android, and it has similar functionality. i've found lots of cool japanese arcade game osts on obscure FM synth chips since. just by randomly going through the archives while taking a walk. basically stuff that's reminiscent of the streets of rage sound.
i haven't had a cellphone for a while, but i borrowed this fat clunky one from my dad that he bought specifically for watching youtube. it has this big integrated loudspeaker. it's perfect for blasting your vicinity with blaring chiptunes XD
i can see myself annoying a lot of folks when i go travelling in the summer, hehe.
going on walks with an app like this is perfect for finding new interesting OSTs. when i'm at home, i tend to only listen to the old stuff i know already, if at all. and i agree, these apps are great, it's like digging for gold nuggets. there's so much trash in these archives, but when you find a nugget it's so fun. it goes for game OSTs as well as chip musician archives.
there should be a random radio play feature in there. something that randomly draws the next tune from the big archive lists.