Motion Math is a producer of mathematics games that I initially tried out back in June. At that time I was having trouble with some of the games crashing. This morning I tried a couple of the games again and did not have any crashes.
The Motion Math games are available in a freemium model. You can play the beginning levels of the games for free, but you have to pay to play all of the levels. The game that has the most free activities is Hungry Fish.
Applications for Education
Motion Math's Hungry Fish could be a good little game for students to use to practice identifying numbers and practice their basic addition skills.