What size are iOS app Settings / Spotlight icons?
iOS developers are required to submit Settings and Spotlight icons for their applications. These icons will appear in Spotlight search results and on the main Settings page. These differ in size from home screen icons.
Settings icons must be created in two sizes:
80 x 80 pixels for Retina display
40 x 40 pixels for standard resolution devices
58 x 58 pixels for Retina display
29 x 29 pixels for standard resolution devices