12 years ago
iTunes gift card
You go to iTunes/App Store on your device or your computer and redeem the gift card. Your account with be credited the amount of the gift card and then you purchase like normal.
Here's Apple's official help page on the topic:
http://support.apple.com/kb/ht1574
Here's Apple's official help page on the topic:
http://support.apple.com/kb/ht1574