As a GM, I’ve never tried tracking people’s uses of their powers/moves/abilities.

However, I do often go through the characters’ sheets and look at abilities or special details which haven’t seen play and think of scenes or NPCs or Bangs which would give them opportunities to do that. It’s a very handy prep technique!

(It gets good when you make pairs of them. “Ben hasn’t used his mind-reading skills, and Julie hasn’t earned XP from interacting with her old mentor.” What’s the most obvious thing? Have a scene with the mentor, and give him a mysterious secret he won’t reveal. Dumb example, but you can see how it works. Very quick and effective prep.)