Read up on the following link:
LINKBasically, you can get up to 9 free apps, with each of those apps you get amazon coins which you can use to purchase more apps. 100 coins is $1.00. So that's 900 free coins, which then you can use to purchase "Grand Theft Auto: San Andreas." (even if it's not compatible with your device, you don't have to install any of these apps) Why purchase Grand Theft? Because it gives you 2000 free coins. So after all said and done you should have 2,200 or so free coins, which is $22 worth of amazon coins to purchase apps. It's free app money, all it takes is 10 minutes max of clicking. Oh, and you must have an Amazon account.
Enjoy!