As Rick Grimes could tell you, a long day of shotgunning zombies makes your shoulder ache from the kickback. That's why pro shooters use recoil pads, little rubbery devices designed with collapsible air pockets inside of them, on the end of the stock to absorb the energy.
A company called BaseOneLabs reckons that the idea behind recoil pads could be used to protect something else: Cell phones.
The company's GunnerCase is not much bigger than the phone it encases, but its sides are lined with "Air Cell" pockets that passively act like little airbags when your phone takes a tumble. And the TPU (thermoplastic polyurethane) the case is made from is anti-lint, so when you pull it out of your pocket it doesn't come out covered in grit.
Circling back to recoil pads for a second, I wish Larry Potterfield, CEO of firearm accessories manufacturer MidwayUSA, was my first shop teacher. For some reason things seem easier to do when you describe them in a friendly Southern accent: