MathIsFun Times Table - Learn Your Multiplication Tables
Isometric Game Art Pack - Extensive library of game art for indie devs
DragonBox Algebra - DragonBox Algebra 5+ - The educational game that secretly teaches you algebra.
Sketch This - Daily drawing challenges
Cool Math Endless Run - Cool Math Endless Run is a monster math game and an endless run adventure.
IsometricSass - Make isometric 2D objects without Javascript