Some of the doors in my house do not stay all the way open and will drift closed, so i designed a simple TPU door stopper cover that can be used as is to replace missing covers or a 6x2 magnet can be added to help keep the door open. 

printed in Overture 95A TPU.

6mm by 2mm magnet for inside the cap

I used a small piece of adhesive pad to stick the magnet to the door, but a small metal plate or shim would work fine i suppose.