
Every app needs an app icon and a launch image. It’s recommended that apps also provide an icon for iOS to display in Spotlight search results and - if necessary - in Settings. In addition, some apps need custom icons to represent app-specific content, functions, or modes in navigation bars, toolbars, and tab bars.
Unlike other custom artwork in your app, these icons and images must meet specific criteria so that iOS can display them properly. All icon and launch image sizes are also documented at the iOS Developer Library under the iOS Human Interface Guidelines section.

Why does your app have that black bar at the top of your screen? Because you haven’t optimized it for the iPhone 5, yet. In this tutorial I will quickly guide you through it.
The first thing you need to do, is to make sure you have the newest version of Xcode (4.5 or greater). The older versions of Xcode don’t contain the new iPhone 5 simulator.
Masking an image enables us to create images with irregular shapes dynamically. Masking is often used to create a user interface that is more compelling, thus more interesting. The apps Boyfriend & Girlfriend use masking to create their shapes and buttons. In this tutorial I want to explain what image masking is, and how to use it in iOS.