Motion Math creates mobile math game suites that are rigorously educational, stylish, and awesomely fun. Play and learn with number sense, the fundamental understanding of quantity, estimation, place value, and mental arithmetic. 

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.