As an iPhone app developer, I agree with your first sentence, but the resolutions are actually the smallest issue. In addition to what has been said in the sibl

As an iPhone app developer, I agree with your first sentence, but the resolutions are actually the smallest issue. In addition to what has been said in the sibling replies, * Designing for iPhone 4/4S and 5/5c/5s is almost the same, at least in portrait orientation. Most layouts are a little flexible vertically - and they have to be, because users might be in a call, or have the personal hotspot active, in which case the OS reserves some space for an additional status bar. Apps have to be flexible vertically, period. * It is much harder to support all the larger text sizes that are available in iOS 7. Much of the iOS UI is built on UITableViews, and these "tables" are terrible when it comes to line breaks. I have increased the text size and many apps can't handle it, including some of Apple's own. * If you are extra masochistic, enable "Button Shapes" and "Reduce White Point" in the Accessibility options in a custom-styled iOS 7 app. For example, this will darken tint colours, which can make buttons harder to read if they are placed over an image (which the OS will not darken).