Privacy
Bare Sudoku stores no personal data: no account, no cookies, no IP addresses. Your current game is saved only in your browser. The site keeps anonymous counters (page opens, games started and finished, level, language, device type and referring site), and the totals are public at baresudoku.com/stats/. The Android app has no internet permission at all.
This policy covers the web game at baresudoku.com, the Android app and the iOS app. None of them shows ads or asks for personal data. The web game sends only the anonymous counters described above, to baresudoku.com itself; the apps do not connect to the internet at all. Questions: open an issue on GitHub.