X-Ray Scanner 2013 is an app for Series 40 that mimics an x-ray scan. When activated, you simply run your phone over a part of your body (or someone else's) and it will seem like you're scanning it and seeing right through to the bones. You can choose between head, hand, body or foot scans.
Of course, X-Ray Scanner 2013 doesn't really scan your body, it merely plays a video to simulate the effect. It's best to study the motion of the video first to help you perfect the illusion.