I am a bit confused now. I read through a lot articles that describe how to implement game center. All of them mention that I have to create an app at itunes connect first.
So do I have to submit my app to iTunes first? Why do I have to do that? Do I have to set a later release date than?
All suggestions appreciated!
You just have to create an App Id on the Itunes Connect. When you create an App Id you just give some meta-data (the most important is the Bundle Identifier) about your application but you don’t have to submit any binaries. You submit the binary application when you want submit it on the App Store.
You must create an App Id because It’ll allow you to use the game center server to do your tests.
There is a very good tutorial on Ray Wenderlich blog: How To Make A Simple Multiplayer Game with Game Center Tutorial