I am implementing an in app purchase subscription model.
Let's say I have an iPhone 3 user which starts the whole purchase process from my application and then exits the application only to continue and fill his app store credentials outside of my app until he is done with the purchase.
How can my app know that the transaction was made upon launch? Also in case I do get this info how can I tell it is not an old purchase for an old subscription period which has already expired?
And last but not least in case the device supports multitasking and the purchase was finished while my app was in the background how will I get notified upon returning to the foreground?
Thanks
Roi