When using NimbleKit 1.9.9 with Xcode 4.5.1 to develop an iOS 6 app, there is a minor bug in the default settings that you’ll want to check for. If you look at the Build Settings tab of the main project file, you might find (as I did) that the iOS Deployment Target is set to 4.0. The trouble is, an iOS 6 app is only backwards compatible to run on devices with iOS 4.3 or later. So change this setting to iOS 4.3, as shown in the diagram above, and then you should be fine. Not changing this setting will result in some build errors that, unfortunately in typical Xcode fashion, do not provide enough detail so that you can actually fix the problem.