Twentyfour Challenge for Android
Excellent game for middle schoolers.
If you like math this game is addicting.
Challenging, but fun, for all ages. My brother is a brilliant mathematician who does stuff like this all day. He'll love the game. But his younger sons in grade school will also love it. They'll even try to beat him at it, and sooner or later they'll succeed. --Fred Stluka
Great for passing time guiltlessly. Features are intuitive and enhance gameplay.
by S####:
Gameplay works well and button placement makes sense. I'd like to see some more recent designs but that's not a problem.