This works in the UK, USA and Germany only however more countries may be added so make sure you look out for it. Also you will need a iDevice (iPhone, iPad, iPod etc.) for you to be able to get a Free iTunes Card, Free iTunes Voucher or a Free Amazon Card, Free Amazon Voucher.

Step 1:
Visit AppBounty from your iDevice (iPhone, iPad or iPod).

Step 2:
Click Enroll Device, then press install.

Step 3:
Go back to the site and click on any of the apps and click go to app store and go ahead and download the app.

Step 4:
Once you have earned enough rewards go to the rewards page and you can redeem Amazon Vouchers or iTune Cards.