We played a game where I would call out a letter and she would find the right light and switch it off. We took turns so she got to use the letter receptively and expressively. Once we were done with that game I just scribbled over the top of the permanent marker with whiteboard marker and it easily wiped straight off. You could use whiteboard marker from the outset but I wanted the letters to not rub off as we played.
This would be cute if you could find grouper fish to put in them or I guess you could use any fish. I would use blue electrical tape or something to go around the lids. My toddler would most certainly open this up and make a mess!
Called to Serve Mission Checklist... I've heard suggestions for a girl's version as well that could include mission or temple marriage at the bottom. I think this would be a good incentive to work toward those goals -- we might have a few more Eagle Scouts around here if I'd had these for each of my kids..djg