App Store Apps can be offered to a third party, whether as a gift, for testing or promotional purposes.
Promo codes can be redeemed directly on the iPhone, iPod or iPad on which it is meant to be installed or to iTunes onto your computer. Redeeming a Promo code from a device will automatically initiate the download of designated app and if done in iTunes and the app will then be synced to all devices which is good for an app like FileApp Pro for which a single download works both on the iPhone and the iPad.
- Open iTunes, go to the iTunes Store
- Click on the "Redeem" link (at the right of the screen in iTunes or at the bottom of the main "Featured" screen on a device)
- If you are not signed in you will be invited to do so
- Enter the code and to get the free download.
NOTE: Codes are valid only for a limited time, hurry!