PowenKo, Mac APP tutorial 001- begin hello world
http://developer.apple.com/library/ios/#documentation/IDEs/Conceptual/xcode_quick_start/010-Tutorial_Using_Xcode_to_Write_Hello_World/hello_world_tutorial.html sample code: 001-Begin-Hello
iOS, Android, Unity3D Education blog,
http://developer.apple.com/library/ios/#documentation/IDEs/Conceptual/xcode_quick_start/010-Tutorial_Using_Xcode_to_Write_Hello_World/hello_world_tutorial.html sample code: 001-Begin-Hello