On Sudoku, you can have fun playing because it's a free sudoku, and you can put your mental abilities to the test, as you will have to use them to progress in the game. The app is composed by 3 levels, and each level has a total of 30 screens, making a grand total of 90 different screens, where you can use your mental ability to get to the 90th screen, which won't be an easy task. For those who don't know how sudoku works, I'll make a short explanation, but there's no better way of learning than actually playing the game.
You need to fill all the squares with numbers from 1 to 9, but you have some rules for filling those squares. The game consists of a 9x9 grid, ha and inside each square you have another 3x3 subgrid, you need to fill the blank spaces, but you can't repeat any number in an horizontal or vertical direction. You can't repeat either any number inside the 3x3 subgrid. You need to be careful, it may look easy but you need to have in mind every other number in the game. If you follow these little instructions, everything will run smoothly.