App Compatibility (iOS & Device)

91% of my users are on iOS 6 already. My app supports back to 4.3, but there's still a handful of users (< 1% of visits) using a previous version that supported 4.2 on iPhone 3G devices.

But in general, it's still pretty easy to support old versions back to at least 5.1, and maybe 4.3. I know a few people who are holding off upgrading because they don't like the new Apple Maps. Do you really want to miss out on that other 9% of users?

Unless you have a good reason not to (i.e.: you really need an API or a bug fix that isn't available on older versions), IMO it's a good idea to support the oldest version that you practically can.

 

Unless your app is using iOS 5 specific functionality, I see no reason to limit your user base. Personally, my current support is as low as Xcode will go (currently it is iOS 4.3), and I'll be following that pattern for my upcoming apps unless I simply can't due to functionality restrictions.