The WipeCoin case is a specially designed iPhone 4/4S case with a built in cleaning disk that can be used to clean the gunk off your phone’s display. The coin stores in the lower right corner of the case, but when you need to use it, it slides out so that you can rub the antimicrobial microfiber cloth attached to the bottom of disk all over the display. When you’re done, snap it back in place. The WipeCoin is made in Germany and sells for $19.99. I think I’ll save 20 bucks and stick with my tried and true cleaning method – rubbing it on my pants leg.