If you have a door that’s sagging or warped and keeps slamming shut, you might find yourself thinking every now and then that gravity is a real pain. But this simple gadget can outsmart it. You stick one part to the door and slot the other part into it. Then open the door until the second part sticks to the wall. From then on, you can always secure the door this way, and it won’t close on its own anymore. Tested for you.