How can I ensure my iPhone app uses the Game Center sandbox?

Deleting the app, logging out from Game Center app, and reinstalling the game from Xcode is what helped over here.

The Game Center Programming Guide has a section describing when the sandbox environment is and isn't used (scroll down to "Testing a Game Center Application").

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.