Required iPhone & iPod touch Screenshot Upgrade for Retina DisplayApple has long supported the inclusion of Retina screenshots for iPhone and iPod touch apps but has not required them, instead allowing developers to continue using non-Retina 480x320 screenshots that are then scaled up for viewing up on Retina devices. But with Retina displays having been included in the iPhone and iPod touch since 2010, the company clearly feels that developers should have already moved to the higher resolution and will not allow developers to update their apps going forward without making the necessary screenshot changes.
When you create or update your apps in iTunes Connect, you must upload screenshots that are high-resolution. We require your screenshots as high-resolution images so that your app is optimized for the Retina display.
The requirements for high-resolution images are 960 x 640, 960 x 600, 640 x 960, or 640 x 920 pixels. Images must be at least 72 dpi, in the RGB color space, and the file must be .jpeg, .jpg, .tif, .tiff, or .png. You can update your screenshot files at any time in iTunes Connect.
The iPad 3 is expected to appear within the next few months carrying a higher-resolution display that will utilize the same ideas as with the iPhone and iPod touch, doubling the display resolution in each dimension to 2048x1536 to allow for sharper content while easily maintaining compatibility with lower-resolution apps using pixel doubling. Apple is of course not yet soliciting developers for high-resolution versions of their existing iPad app screenshots, but enforcement of higher-resolution iPhone and iPod touch screenshot requirements will also make those App Store images appear sharper on both current and future iPads.