So you would like to turn your door into a cat door? KittyKorner has you covered. It is a clever hinge that makes your door cat/dog friendly. You can install it with a simple cut to your existing door. You will be able to lock your KittyKorner in an open or closed position.
This project is currently on Kickstarter. You can find out more about it here. What do you think? Grab or pass?