A father-and-son team from a small Ohio town, Kitty Poo Club makes an all-in-one cat-litter system that pairs a fresh disposable box with litter delivered to the door. Its boxes are made primarily from recycled cardboard, designed to be recycled again after use, and feature a patented leak-proof lining. The company says it has shipped more than 3 million boxes and built its business around making litter-box care easier for cats and their owners.