Bare Sudoku

Bare Sudoku is a free Sudoku with nothing in the way: no ads, no account, no tracking and no in-app purchases. Play in the browser in 223 languages, install the 25 KB Android app that asks for no permissions and never connects to the internet, or use the native app for iPhone, iPad, Mac and Apple TV (currently in App Store review).

Four levels (Easy, Medium, Hard, Expert). Every puzzle has exactly one solution and can be solved by logic alone. Notes, undo, erase, fill all notes with one tap, digit lock for fast entry, mistake marking you can turn off, dark mode and full keyboard support. On Apple TV the whole game works with the Siri Remote. Hints explain the technique instead of just revealing a digit: singles, locked candidates, pairs and triples, X-Wing, Y-Wing, Swordfish and XYZ-Wing.

Works offline as a progressive web app. The same game and the same rules on every platform. Open source under the MIT license.