Sudoku Fun is a free gaming app that gives you the ability to play the popular sudoku number logic game right on your Android device. The game has a relatively simple premise, but it can be insanely difficult to fill every box on the board, especially for games at the higher difficulty settings. The goal of the game is to fill the empty boxes on the 9x9 grid with digits ranging 1 through 9. The trick is that you can't have two of the same number in any horizontal or vertical line, and you can't have two of the same number in any of the nine smaller grids of nine boxes that make up the entire board. In other words, when you complete the puzzle, each of the nine smaller outlined grids should contain digits 1 through 9, and so should every horizontal and vertical line.

This version of the game has a sleek, modern interface and five difficulty settings to choose from. Those settings are beginner, easy, medium, difficult, and expert. You can use pencil marks to help with your logic trails, and there is a built-in hint feature that helps guide you through the more difficult game boards.