What is the Mobile Sudoku game, how does it work?

According to the introduction of Joerg Jahnke, Mobile Sudoku is a Puzzle game on the Android platform. There is currently a 1.13.4 version released on Jun 18, 2017, you can see the details below.

Sudoku implementation which can automatically generate an unlimited number of boards for six difficulty levels. It supports touchscreen and keyboard control.

Uses global leaderboards where you can compare your highscore to that of other players, and allows challenge games.

Ad-supported version. App permissions required for ad retrieval.