Now developers will be able to use tools familiar to any OS X developer, such as Instruments, Xcode and Interface builder, alongside a new tool, the iPhone simulator, to craft applications.
Testing and debugging of coverage files for routing apps is only supported during development through the Xcode Run workflow. (You can specify the coverage file for a given Run scheme using the Options pane of the Run section of the scheme editor.) Apps that are archived and distributed (outside of the App Store) onto devices will not have access to the app's coverage files.