IconRounder is a very simple app for iOS developers and graphic designers that are creating icons for iOS apps. It allows the user to quickly verify that an icon is within the Rounded-Rectangle-Alpha-Channel mask that Apple automatically applies to iOS icons. It also allows you to see how the icon will look after Apple applies the Shine FX to the icon.
You can save an icon at any size from 16 pixels to 512 pixels with the Rounded Corners and optionally with the Shine FX applied to the icon. This was the original impetus for writing this app: So I could have a convenient way to create icon images of each of my apps, for my website. Alternatively, you can use these modified icon images as your actual icons that you include in your app bundle. Just remember to set the appropriate entries in your plist file.
In the screenshot below, the imageWell on the left side is where you drag your icon to. Select a size for the image by dragging the Size Slider or tapping one of the Size Buttons.