What is the stupidest startup idea you’ve ever heard?

I didn't hear it, but think it: (it's inspired on skateboarding and fingerboard), a mobile application that has a white (or any color on the screen) and when you touch any part of the screen it turns red, and on the screen will be display some "tricks" to do with your phone, like "simple spin" (you have to throw your phone, make it spin and catch it again) without touching the screen. Basically if you touch the screen is like falling on the skateboard