DragonBox Algebra - DragonBox Algebra 5+ - The educational game that secretly teaches you algebra.
Yasminoku - Sudoku game and solver totally written in DHTML.
Cool Math Endless Run - Cool Math Endless Run is a monster math game and an endless run adventure.
HoDoKu - HoDoKu is a sudoku helper written in Java and available in English and German.
Akribian - Akribian turns children into Mathemagicians with their new iOS app, Count on me!
nsudoku - A Sudoku game made with ncurses.