Sum Fun - A fun number puzzle game for iPhone and iPad.
NumberDrop - A uniquely challenging math puzzle game.
HoDoKu - HoDoKu is a sudoku helper written in Java and available in English and German.
dworksheets.com - Free K-12 math worksheets to assist students, teachers, parents & tutors to practice, teach or prepare grade school assignments, classwork or homework questions & answers is available online in printable & downloadable format.
Griddition - Griddition is a challenging numbers puzzle where you must fill a grid with numbers, Sudoku-style.
Minimal Sudoku - Minimal Sudoku is an easy to use, clutter-free classic sudoku game which is designed for iOS 7.