Hi All, especially Patrick,
Borrowed this contraption when I broke my wrist, and recently when I had a finger operated on. Toast was difficult for me too!
This plastic board sits on the edge of the bench, or on edge of board as here. Toast placed like so and buttered with right hand does not run away when butter spread. Can also be used left handed.
Am sure you could rig up a set of right angled wood bits, or even an old (clean!) picture frame so that it stops the toast from running away.
Big Hugs everyone!