If you have a Barnes and Noble Nook tablet you would have likely have seen the account management system. This was devised so that families who share the same device can better organize their e-books, magazines, newspapers or Android apps. Today, the Nook App for iOS has been updated with the same functionality.
I have always been a fan about the way parent and child accounts have been managed on Nook tablets. Now that it has been ported to iOS, all past purchases can be synced over and new accounts can be established. Sadly, if you do have a Nook tablet the same accounts you have on those devices will not carry over to iOS, you must establish new ones.
The updated app right now is on iOS only, with no word yet if the Android app will see the same system ported over.