iOS Icons

Universal apps icon requirements.

Image Size (px)	File Name	Used For	Required Status
512x512	iTunesArtwork	Ad Hoc iTunes	Optional but recommended
114x114	Icon@2x.png	Home screen for iPhone 4 High Resolution	Optional but recommended
72x72	Icon-72.png	Home screen for iPad compatibility	Optional but recommended
58x58	Icon-Small@2x.png	Spotlight and Settings for iPhone 4 High Resolution	Recommended if you have a Settings bundle, otherwise optional but recommended
57x57	Icon.png	App Store and Home screen on iPhone/iPod touch	Required
50x50	Icon-Small-50.png	Spotlight for iPad compatibility	Recommended if you have a Settings bundle, otherwise optional but recommended
29x29	Icon-Small.png	Spotlight and Settings	Optional but recommended

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

Basically 512/80 == 114/18 == 72/11 == 57/9 == 6.4

Reference:

1) http://stackoverflow.com/questions/2105289/iphone-app-icons-exact-radius

2) http://hicksdesign.co.uk/journal/ios-icon-template-for-illustrator-cs5

3) http://blog.cocoia.com/2010/iphone-4-icon-psd-file/

4) http://hicksdesign.co.uk/iconreference/