Me and my brother both recently got apple devices (an ipad 2 and an ipod touch 4th gen). We both have separate apple accounts. It just occurred to me that this means we have to pay for everything twice if we want it on both devices. Could I just log out of the app store and log in as my brother any time I wanted to download something purchased under his account? Would this work? And when I sync it back to my computer, would it be deleted?