Made for iPhone 3G
This is a Game Center patcher. It allows the game center to detect GC aware games and also patches games so that they don't disble Game center support by looking at Iphone model.
After installation, go to Settings and open 'GC Patcher'. Manage the application preferences there.
Most of the games just ask GC to login, which this application will fix. However certain games, like "Saving Private Sheet" and "Fruit Ninja" check the iphone model before contacting GC, for them game patching required, so enable the option for them in the settings.
For questions, check with me at twitter @ShaniDurrani or http://shanidurrani.tumblr.com/
Also make sure you copy the 4.2.1 Game Center files on your Iphone 3G
This will not add any icons to your home screen. Options can be configured in your Settings app.