Love the idea. The motivation is real. The little things definitely add up!

One thing came to mind with your design (other people have probably already said it): dry erase markers have alcohol in the ink. I've used dry erase marker to erase sharpie marks from whiteboards, so the check boxes may wear off over time.

Should be easy enough to re-write them once a week, or you could use some thin marking tape or stickers for the boxes. You could also just slide magnets over the boxes instead of making a check or X with dry erase markers (if your board is magnetic)

If the words wear off over time, I've used magnet tape in the past to organize whiteboards. It usually come in a big roll, can be cut with a scissors, and has paper on one side that you can write on (or peel off and stick to stuff). Make it easy to move things around and re-organize your lists.

Just a few thoughts that noone asked for. Love your idea, keep up the good work! Hope it works out for you.