Sudoku.by BinG vs TwentyFour

Every puzzle has an answer. A quiet sheet of paper and a problem that works out. sudoku is a minimal, restrained take on the classic — no ads, no tracking, no noise. Just you and the grid. Warm paper white, a single Morandi accent, monospace numerals under a serif title. Open it and solve; finish and let it go quiet. Four difficulties Easy / Medium / Hard / Master. Master ships with world-renowned classic puzzles and a graded bank — from first steps to the very edge. An AI coach that teaches you to think Not just answers. Naked singles, hidden singles, naked pairs, pointing pairs, X-Wing — each technique highlighted right on the board, so you see the logic instead of being handed it. Made for beginners, too A four-step tutorial on the real board: from the rule to the deduction, then straight into your first game. Paper mode Solve like it's newsprint: no mistake limit, nothing flagged, nothing highlighted. The verdict is yours alone. Tools that stay out of the way Pencil notes, undo, erase, hints; instant conflict flags and soft region highlights — all switchable. And more • Bilingual English / 中文, switch anytime • Five Morandi accent colors — pick your taste • 17 illustrated guides, from the rules to master techniques • Share a puzzle as a text token; challenge a friend on the same board • Best times and full history • Carefully tuned haptics and sound • Fully on-device — your data never leaves your phone Pay once, yours forever. No subscriptions, no consumables, no ads. — Independently designed and built. One person, quietly.

Make exactly 24 using four numbers—and discover how many elegant paths hide in simple arithmetic. TwentyFour is a calm, handcrafted number puzzle for iPhone and iPad. Tap cards in calculation order and choose +, −, ×, or ÷ either between the two cards or after selecting both. Keep combining until one exact result remains. Every number must be used exactly once. Features: • 120 verified puzzles across six progressive chapters • Exact fractions and negative intermediate results • Step hints, undo, redo, restart, and full solutions • Three-star goals based on hints, time, and efficient moves • A deterministic daily challenge that works offline • Free practice with adjustable difficulty • Achievements and local statistics • Dark Mode, Dynamic Type, VoiceOver, and Reduce Motion • No ads, accounts, in-app purchases, analytics, or network connection There is no failure countdown. Take your time, experiment, and build stronger number sense at your own pace. Can you make 24?