On AnkiMobile, whenever we find we want to use a feature or library that is much easier or only possible on later iOS versions, we review market share. We recen

On AnkiMobile, whenever we find we want to use a feature or library that is much easier or only possible on later iOS versions, we review market share. We recently started retiring 4.3, and will soon retire 5. We already develop some new features only for iOS6+ devices, and simply decide at runtime whether they are to be used. It's not a huge pain, but it's a prominent feature of developing for devices that are frequently updated. We always use the latest XCode and the latest SDK. Often there are language features that greatly reduce development time, like the NSDictionary/NSArray literals for example. The only downside is that later XCode versions don't support low-iOS version simulators, so you have to test on-device only when supporting older devices. But this all helps justify to users when you stop supporting older devices.