In June Apple announced new size requirements for submitting iOS apps that would be starting in July. This requirement stipulates that all apps have to ship with an icon measuring 1024×1024 pixels for Retina display devices. Now developers are reporting that the same requirement applies to Mac OS X apps being sold through the Mac App Store.
The reason for this is Apple’s newest MacBook Pro with Retina display, and any Macs that are likely to come out in the future with Retina display. 1024×1024 apps are unnecessary on other machines as some don’t even have 1024×1024 displays. For instance, the 11-inch MacBook Air has only 1366×768 resolution, which means these bigger icons won’t even fit on the screen.
The biggest issue with this is that 1024×1024 icons are much bigger and therefore take up much more space than the previous 512×512 icons. It also means app packages get bigger and storage space decreases even faster with a single app. Developers have no choice but to submit apps of this bigger size as the Mac App Store will simply reject them until it is the proper size.