Grafite Sudoku

Grafite Sudoku is a free Android sudoku app built around one simple idea: a real, complete sudoku experience with no compromises. No ads interruptingyour game. No tracking following your data. No account required to play. No subscription hiding good features behind a paywall.

Every puzzle is generated and verified to have a guaranteed unique solution, with an added anti-obviousness rule that avoids rows, columns, and boxes with too many given numbers — the cap scales with difficulty, from generous on Easy to strict on Expert. The result is puzzles that feel properly challenging at every level, not randomly generated approximations.

Beyond the four classic difficulty levels, the app includes a Zen mode with no timer for relaxed play, a Time Attack mode with a real countdown (Normal and Extreme) for players who want pressure, a daily challenge shared by every player, and direct duels where you can challenge a friend using a shareable code on the same puzzle.

For players who want more depth, there's a progression system: levels with titles inspired by Japanese hierarchies, 30 achievements across six categories (speed, consistency, mastery, exploration, challenges, Time Attack), and six evolving avatar lines in a Japanese watercolor and ink-wash style. None of it requires an account or an internet connection — everything runs and stays entirely on the device.

Privacy here isn't a marketing claim, it's a structural choice made from day one: no backend, no third-party SDKs, no analytics beyond Google Play's own free and anonymous console statistics. Even friend duels work through a local code rather than any server.

Grafite Sudoku is free and will stay free. It's supported only through voluntary donations — never required, never pushed with in-app popups. It's a hobby project built by a solo developer with no prior programming background, made for people who just want to play real sudoku without being the product.