It is a free Sudoku logic game witch contains 5000 puzzles for beginners and experts.
You can also enter your own puzzle and solve it using Sudoku Expert.
You can use facilities such as selecting zones automatic determination of numbers that can be inserted into the fields board validation hints etc. however this has an impact on the result.

The game is created by an enthusiast. It is completely free does not show any ads and does not require unnecessary permissions. It has a very clean and simple interface.

I'm looking for beta testers:
https://play.google.com/apps/testing/com.blogspot.aeioulabs.sudoku

Sudoku (数独) is a logic-based combinatorial number-placement puzzle. The objective is to fill a 9×9 grid with digits so that each column each row and each of the nine 3×3 sub-grids that compose the grid contains all of the digits from 1 to 9.