There are many websites and apps that allow you to give and receive FREE gift cards via Facebook! Here are a few of them:
Your Facebook friends are automatically shown, and you can give various free gift cards for birthdays or just because! You also have the option of adding more money to a gift card. Make sure you read the fine print, as some of the gift cards can only be redeemed on a mobile device.
My Gift Wand
My Gift Wand is the same concept as Wrapp, although they only offer a limited amount of one free gift card per day. The free gift card of the day goes live at 12 PM EST. There are also gift cards for purchase.
Boomerang is a gifting app that allows you to give free gift cards also! They have local deals in just a few cities right now, but I'm sure as they expand and grow, they will include new cities. Check out the national deals to see what is available for you to gift!
Another easy site that reminds you of friends birthdays and lets you give gifts "just because"!