I recently published the Legacy Weapon, as a supplement for 1 on 1 play in Dungeon World.
The Legacy Weapon is its own playbook that is designed to complement a single player (playbook). It provides a way to give that character additional moves that will facilitate 1 on 1 play.
You can hear a bit about it from Jason Cordova on Discern Realities Episode 41.
You can pick it up on DriveThruRPG here…