Yes, that's what I do, although I usually don't let that many hours pass without checking on my pets (I have 3 pets on 3 different devices right now)! I normally only launch the game to check on them and play with them every 2-3 hours, except for overnight. I play with them until they're tired and go to sleep, then I exit the game, sometimes to run other applications and sometimes just turn it off. I hope that helps clear things up!