Torn City
http://www.torn.com/350465
You play it in browser, I don't think there's an App for it yet? It's a text based RPG. I've actually been playing it for 10 years... Lol! I did have several years off here and there mind. You do crimes, you go to the gym, attack/mug people, Join Factions (Should start a CAG one up maybe?) and level up. There's loads of extra things to do on there too, Casino, Racing, place/collect bounties, etc etc.
It is all time based though, so your nerve and energy refill bit by bit 5-10-15 minutes at a time.
Great time waster for toilet breaks that require sitting down. Just sit down, do your crimes, go to the gym/ attack people, check messages, join a race, gamble, and get shit done!