Sample image of a blurred edge sphere created with the iPhone app SphereLens by Salamander Factory Co.
The SphereLens app is currently free for the iPhone in the AppStore. The app is simple in that it applies a sphere effect to images you've taken with your iPhone. There are a few variations that can be made such as the sphere, or you can have a solid or blurred edge to the sphere. If you're looking for a way to create one sphere in the center of an image, this free app is for you.