HoDoKu - HoDoKu is a sudoku helper written in Java and available in English and German.
Sum - Simple Maths Puzzle - How fast can you add two numbers?
Yasminoku - Sudoku game and solver totally written in DHTML.
Griddition - Griddition is a challenging numbers puzzle where you must fill a grid with numbers, Sudoku-style.
USB Sudoku - A very small program for playing the original game of Sudoku.
Sum Fun - A fun number puzzle game for iPhone and iPad.