Undoku is logic game very similar to sudoku and great for all ages.

42000 grids ranging from small 8x8 up to large 12x16.

The goal is simple; fill the grid with numbers so that each number appears exactly once in each row and each column.
Some cells on the grid cover more than one row or column.

Easy, medium and hard difficulties with hints for all difficulty levels. You will never be left without a hint if you need one.

Smaller grids are great for younger players or if you just want a quick game. Larger grids will provide a challenge to even the best puzzle solvers.
Grids can be zoomed in and out using a spread and pinch motion to easily complete large grids even on smaller devices.