You don't need to change much between accounts. Have iOS connect to two different icloud accounts at once for mail, pictures and everything that is synced. Display the necessary content for each account. Mail can already display several accounts at once. Just hide those that are not necessary in that session. Do the same for pictures and favorites and some other stuff to begin with. I don't think it would use more resources than now.
3/10/14 at 6:49pm