So if I unlock my iPhone 5, and take my phone to another country and insert a different sim card (that countrys' sim card), what happens to my existing apps and data on my phone? Does it all stay there? Obviously apps and data (Notes, Calendar, etc) isn't being backed up because it does not have iCloud or Apple Sim card, or does it? And once I come back to USA and insert my original AT&T Sim Card, will my new data override my existing data on my phone or will it go back to the way it was?