ios game center tutorial

網上找到兩篇很好的ios game center入門教程，在這裏分享下：

part 1 (主要是iTunes connect裏面怎麼樣設置app) : 

http://mobile.tutsplus.com/tutorials/iphone/ios-sdk-game-center-achievements-and-leaderboards-part-1/

part 2 (主要是編寫代碼實現Achievement和Leaderboards的操做) :

http://mobile.tutsplus.com/tutorials/iphone/ios-sdk-game-center-achievements-and-leaderboards-part-2/