@required
iPhone 3GS or before : 57px
@optional
iTunesArtWork : 512px - Project에 포함시키지 않아도, App등록시 가능함.
iPhone 4 or later : 114px
Ipad : 72px
Spotlight for iPhone 3GS or before : 29px
Spotlight for iPhone 4 or later : 58px
Spotlight for iPad : 50px
iOS가 점점 지저분해진다.