Sudoku Dan Lite is a free introductory version of the two-player game of skill that uses a sudoku grid as the board. It isn't a puzzle or a race, but a tactical challenge like Chess or Go. Play against the computer or with a friend. A full set of rules comes with the app. Three more skill levels and Game Center features are available if you buy the full Sudoku Dan app, already available.
With Family Sharing set up, up to six family members can use this app.