I used the have an iPod 4th generation and the music was really annoying after time, so I'd usually put in headphones and listen to my stuff. But now I have an Android, which is BETTER THAN APPLE, and thought the app was slightly dead without the background. I could just put headphones in, but too much of it can damage your ears. LONG REIN THE ANDROID!
Honestly sound doesn't change the way this game will work, regardless if it's put into Android devices or not. I had an iPod Touch with the sound, and I wouldn't bother about it being absent.
They haven't updated that portion of the game yet. I doubt they will forget about it tho, just give it some time