At iOS pokerstars, it's fine, except there are no home games. The 888poker case looks a little worse. You can not play on multiple tables at once. You also can not go to the cash tables selection view.
From my point of view, iOS is very bad for playing, when I’m playing - I can’t concentrate, I don’t feel like I’m playing for real money, it seems that it is play money so I don’t really think about the game, I think Android is better in this question, but I don’t recommend to play on phone at all.
I play for money on my phone but win less when I'm on my phone. Less options on apps then sites. But thank God for mobile apps. When there is an emergency I take my phone and keep playing.
In terms of numbers, I think Android has more sites. iOS is somewhat restrictive with which apps you can play on. That can be a good thing since the developer is vetted.