This is not the most simple hook I ever made for my Skadis (that one was for my metal ruler), but it's by far the one I enjoy the most.

It's designed so the hole on the knife easily slips onto the hook, it's also facing slightly up so the knife can't fall down. On the back of the lower sprocket it a little “hook”, so it grabs to the rear of the board and doesn't come off as easily.

Maybe someone can enjoy these simple things just as much as I do