Store it like any other object you'd store. It's an object. Retain it. For example, under ARC you'd simply assign it to a property. Remember to register for ACAccountStoreDidChangeNotification just in case the user does something, such as deleting this account, behind your back; if the notification arrives, your supposed to release your ACAccount object and fetch it again.
The account is uniquely identified by its identifier
, so on subsequent launches of your app you can fetch it again with accountWithIdentifier:
.