Sudojo vs Sudoku Istind

Sudojo is the ultimate Sudoku learning platform that teaches you how to solve puzzles — not just gives you answers. Progress from beginner to expert through a structured belt system while mastering 60+ real solving techniques used by championship players. DAILY CHALLENGES • A fresh puzzle every day tailored to your skill level • Track your daily streak and compete with yourself • Share your completed puzzles with friends LEARN 60 SOLVING TECHNIQUES • Each technique includes step-by-step explanations and practice puzzles Basics: Full House, Hidden Single, Naked Single Pairs & Tuples: Hidden Pair, Naked Pair, Locked Candidates, Hidden Triple, Naked Triple, Hidden Quad, Naked Quad Fish: X-Wing, Swordfish, Jellyfish, Squirmbag Finned Fish: Finned X-Wing, Finned Swordfish, Finned Jellyfish, Finned Squirmbag Sashimi Fish: Sashimi X-Wing, Sashimi Swordfish, Sashimi Jellyfish Franken Fish: Franken X-Wing, Franken Swordfish, Franken Jellyfish Wings: XY-Wing, XYZ-Wing, WXYZ-Wing, VWXYZ-Wing, UVWXYZ-Wing, TUVWXYZ-Wing, STUVWXYZ-Wing Single-Digit Patterns: Skyscraper, Two-String Kite, Empty Rectangle, Simple Coloring, W-Wing, Remote Pairs, Crane, Firework Unique Rectangles: Type 1, Type 2, Type 3, Type 4, Type 5, Hidden UR, Avoidable Rectangle Almost Locked Sets: ALS, ALS-XZ, ALS Chain, Sue de Coq, Death Blossom Chains: X-Cycles, Grouped X-Cycles, X-Chain, XY-Chain, AIC, Medusa Coloring, BUG+1, Forcing Chains, Forcing Net SMART HINT SYSTEM • Hints that teach you the technique, not just the answer • Visual highlighting shows exactly which cells and candidates matter • Step-by-step walkthrough of the solving logic • Learn the "why" behind every move BELT PROGRESSION SYSTEM • 12 belt levels from White Belt (beginner) to Black Belt (master) • Each belt introduces new techniques and harder puzzles • Earn points, unlock badges, and track your improvement • See your solving skills grow over time 12 DIFFICULTY LEVELS • Beginner to Extreme — there's always a new challenge • Each level focuses on specific techniques • Free access to foundational levels • Premium unlocks advanced and expert difficulties MORE FEATURES • Enter custom puzzles manually or scan from paper • Multiple display modes: Numbers, Kanji (漢数字), or Emoji • Pencil marks with auto-candidate mode • Timer and error highlighting (optional) • Dark mode and 16 language options • Sync progress across devices with your account • Works on iPhone, iPad, and Mac FREE & PREMIUM • Play daily puzzles and beginner-to-challenging levels for free • Subscribe to unlock advanced levels, expert techniques, and full hint access • Blue Belt: Unlocks Difficult, Intense, and Expert levels • Red Belt: Unlocks all levels including Brutal and Brain Freeze Whether you're picking up Sudoku for the first time or you're an experienced solver looking to learn advanced techniques, Sudojo is your path to mastery. Terms of Use: https://sudojo.com/en/terms Privacy Policy: https://sudojo.com/en/privacy

A quiet sudoku for iPhone. No ads, no accounts, no tracking, and nothing that nags you from a notification. Istind is built around one idea most sudoku apps get backwards: the app should not do the thinking for you. A digit that breaks a rule is marked, because that is a rule and not a judgement. A wrong digit that still fits is left alone — finding it is part of the puzzle, exactly as it is on paper. A COACH THAT EXPLAINS INSTEAD OF ANSWERING Stuck? The coach walks the next logical step in four stages: where to look, what the evidence on the board is, why it follows, and only then the move itself. Stop at any stage and take it from there. Nothing is locked, deducted or scored for using it. A PUZZLE CHOSEN FOR WHAT YOU ARE LEARNING Once you have finished a board, Istind can offer one whose solving path uses the technique you are next in line to learn — and the coach teaches it as you go. THE SAME BOARD AS EVERYONE ELSE, ONCE A DAY The daily puzzle follows a weekly rhythm from Easy on Monday to Expert on Saturday. Miss a day and the archive lets you play it later — it fills the calendar, but it will not repair your streak. SIX LEVELS, ENDLESS PUZZLES Every board is generated on your iPhone and verified to have exactly one solution. Nothing is downloaded, so it works with no signal at all. Notes, undo, conflict highlighting, full VoiceOver support, Dynamic Type, and a light and dark paper design made to be easy on the eyes late at night.