A free app is the new coolest thing for DIY skin cancer diagnosis. As long as you’re willing to take 23 nude photos of yourself. If there’s one thing that celebrities and politicians have taught us, it’s that having naked photos of yourself on your cell phone is never a good idea. Or perhaps -- unless you’re doing it to detect skin cancer? Those concerned about modesty might prefer to risk the disease, but a new app for mobile phones out of the University of Michigan allows users to take photos of their skin -- all of it -- as a basis for comparison should suspicious moles or lesions be detected.