If you’re a developer designing an app for iOS 7, you already realize that the operating system’s drastic change in appearance will quickly make your app look dated and out-of-touch with Apple’s new OS.
Furthermore, if you don’t go with some of the iOS 7 UI items, it will quickly ruin some of the continuity between your app and Apple’s software. It’s best to get it as close as possible, so that users feel like your app is all one part of their iOS experience.
You can now download a PSD (Photoshop document) of the GUI from Teehanlax.com. It’s not designed to that people can use the elements as their own. It’s just a tool to aid them in developing apps for iPhone. You can check it out here.