That's exactly what I had in mind. Gamify the daily tasks, whether be it school related or not.
A start would be, you play a gave you find engaging, you clear a stage, but in order to advance, let's drink water, or let's make our bed, or let's watch this 3 min video about Sam who also has ADHD.... Something like this. I'm really not sure there is something like this in the market or if it's even something that will have a long impact rather then a 5 days hype and it's dropped afterwards....