DoorKeeper

The DoorKeeper attaches to the bottom of your door and keep the door from auto-closing or auto-opening -- e.g. if your door is not hung completely plumb. Note that this version is intended for use on carpet.

I've included an STL which should be usable a standard 1 3/8" thick door which is ~15mm above the carpet.

See it in action: https://www.youtube.com/watch?v=PbiPLvzjrho