American Airlines, United Airlines, Virgin Airlines, and Delta Air Lines has confirmed that they have started supporting Apple’s Passbook app, which will debut with iOS 6 this month. Passbook is like a “virtual wallet” for people to store loyalty cards, boarding passes, and other electronic documents. When a user arrives at a certain location, the appropriate loyalty card will load on the lock screen, which will allow the user to show the pass without having to unlock the iPhone. The user will also receive a push notification if a flight is delayed or if a concert is cancelled. Passbook users will also be able to check balances on gift cards and reload them.