iphone icon的圓角距離

• corner radius for the 512x512 icon = 80 (iTunesArtwork)
• corner radius for the 114x114 icon = 18 (iPhone/iPod touch (Retina))
• corner radius for the 72x72 icon = 11 (iPad)
• corner radius for the 57x57 icon = 9 (iPhone/iPod touch)

資料來源
http://stackoverflow.com/questions/2105289/iphone-app-icons-exact-radius