Apple has recently announced that, starting from February 1st, all iOS apps and updates need to work seamlessly with iOS 7.Starting February 1, new apps and app updates submitted to the App Store must be built with the latest version of Xcode 5 and must be optimized for iOS 7.

In technical terms, now all the apps submitted to the App Store need to be built with iOS 7 SDK and Xcode 5.x or later. Anything that does not conform to these terms will be rejected.

Does this mean that my app won’t work on older versions of iOS?
No. The SDK and the minimal supported versions of iOS are not the same thing, and your app will still work on old versions of iOS you want to support.

Is changing the SDK a lot of work?

It depends. Just switching the SDK is done. Not so fast! This doesn’t mean the app update is now ready for submission to the App Store. There are plenty of small UI problems to fix.

Apple is pushing hard to keep the users up to date with their release cycle, but there will always be a minor percentage of users who do not update, whatever reason there might be for not doing so.

You’ll now go through the app and fix these issues one by one. When you do this, it’s easiest to remove all the custom graphics and strip the app down to its bare essentials. This allows you to focus on the more important problems first. Once everything works properly, then you can then add the graphics back in.

Tips:

  • The tint color is blue by default, but by changing this color you can immediately give your app its own unique style with very little effort. Views inherit the tint color from their parent views, so by setting thetintColor property on the app’s single UIWindow instance you effectively change the tint color for every view.
  • iOS 7 introduces a new feature to help organize your images: asset catalogs. An asset catalog is a special folder for your images managed by Xcode that makes it easy to associate multiple versions of an image (i.e. normal version, Retina version, 4-inch iPhone version, iPad version, etc) with a single filename.