Here is a waterproof kit for iPhone that lets you capture beautiful videos with it underwater. The Optrix case is waterproof to 33 feet and drop tested from 20 feet. It has a crush resistant body and 4 interchangeable lenses. This easily mountable case lets you use your smartphone as a premium action camera.
The Optrix by Body Glove case comes with telephoto, macro, normal, and wide-angle lenses. It is available around $130 at this time.