Sudoku by Upstory

No ads, ever. No subscriptions. Works fully offline, with every puzzle built in. No tracking and no accounts. Sudoku by Upstory is classic 9 by 9 Sudoku on a grid that reads like a printed page: warm paper, serif digits, fine lines, and nothing between you and the board. Fill every row, column and box with the digits 1 to 9. Every puzzle has exactly one solution and can be solved by logic alone, without guessing. It opens straight into the puzzle you left, and every move is saved as you make it. Undo is unlimited. Mistakes can be marked as you go, but there is no mistake limit, no score and no game over. When you complete a row, column or box, a soft wash runs along it. When the last digit goes in, you see your time, and a new puzzle is one tap away. Hints teach the step instead of just giving the answer. Ask for one and the cells involved are outlined, and a single plain sentence names the technique, from a hidden single to an X-Wing. Tap Hint again to fill it in. If a digit you placed is wrong, the hint points to it first. Hints are unlimited, with nothing to earn or buy. Entering digits is quick. Tap a cell, then a number. Notes mode adds pencil marks, and a placed digit is cleared from the notes in its row, column and box. Press and hold a number to lock it, then tap cells to fill them one after another. With no cell selected, tap a number to see everywhere it sits. Under each number, the pad shows how many are left to place. Six levels, each graded by the techniques its puzzles need: Easy, Medium, Hard, Expert, Master and Extreme. 1,800 puzzles are built into the app, 300 at each level, so a new one is always ready, online or not. Options Settings holds Mark mistakes, Remove notes automatically, Highlight matching numbers, Highlight row, column and box, Show time, and Haptics. It is also where you choose the level for your next game. The clock starts with your first move and pauses while you are away. Settings also keeps a record for each level: puzzles played and solved, your times, and how many you solved without hints. Designed for iPhone and iPad. On iPad in landscape, the grid sits beside a 3 by 3 keypad. With a hardware keyboard, arrow keys move the selection, digits place, Shift with a digit writes a note, Delete erases, and Command-Z undoes. Accessibility VoiceOver reads every cell by row and column, with its digit or its notes, and announces each hint as it appears. Text around the board follows your Dynamic Type size. Reduce Motion turns movement into simple fades. Light and dark appearance follow your device. Digits are large, with high contrast. Sudoku by Upstory is one of seven Quiet games from Upstory.