Ok, this isn't a trainer but a generator, and no, is not for a game, but for XBOX Live. With this you can get a fully working code for a 12th months membership of XBOX Live Gold. How it works? Easy... Well, not really, it cost me a lot to get this thing to work, but in little words, it generates a code and then it search if is already used... if not, then it register the code generated in the Microsoft server so you can use it to redeem the subscription. All of this behind a VPN.
When the installation is over, the generator will open automatically. You can find it in your desktop after that.