Sudokoi vs Slatework

Sudokoi started from one question: what if a sudoku app actually respected the player? The ones that dominate the store today are built to maximize taps — to interrupt, to nudge, to monetize the next 30 seconds of your attention. Sudokoi is built for the opposite: a single quiet puzzle, played at your own pace, that's still waiting for you when you come back. WHAT'S INSIDE • Four new daily puzzles every day • Four difficulty tiers — Easy, Medium, Hard, and Nightmare — generated, then verified by a human-style technique solver so the ratings are honest • Corner notes, center notes, and auto-erase across peers (or turn that off and pencil it yourself) • A "Fill Notes" shortcut for when you'd rather skip the bookkeeping • Hints that don't just point at a cell — they explain the technique. Naked Single. Hidden Pair. X-Wing. Y-Wing. The hint sheet shows the digits, the cells, and the reasoning, so the next puzzle gets easier • A non-punitive mistake counter. We track if you placed a wrong digit, but we never lock you out or end the game • Per-difficulty stats: best time, average time, games won • Music, sound effects, and haptics — all optional, all togglable in Settings WHAT'S NOT INSIDE • No ads. Not banners, not interstitials, not "watch an ad to continue." Nothing. • No 3-strikes-and-out. No restart-from-scratch. • No identity tracking. We use anonymous diagnostics to tune defaults and you can turn even that off in Settings. • No subscription. Sudokoi is free. If we ever add paid features, they'll be additive — your daily puzzle, your four difficulties, and your stats stay free forever. THE ENGINE Sudokoi's puzzles come from a backtracking generator that produces a unique solution for every grid, then verifies the difficulty with a logical solver — the same code that powers the hints. The solver knows every standard sudoku technique through Jellyfish and beyond, which is why Hard and Nightmare actually feel like Hard and Nightmare. ONE PERSON, IN THE OPEN Sudokoi is built by one person. The privacy policy and terms are honest documents you can actually read at sudokoi.com. Feedback goes to a real inbox at feedback@sudokoi.com and gets a real reply. If you've ever wished a sudoku app would just shut up and let you solve, this one's for you.

Slatework is a collection of thirteen classic logic puzzles. It opens on a grid, works with no signal, and asks you for nothing: no account, no ads, no subscription. Every board is generated on your device the moment you ask for it, and checked by a solver before you see it. Each one has exactly one answer, reachable by logic alone — no guessing at any difficulty, and no pack of puzzles to run out of. Thirteen types • Killer Sudoku — sudoku with cages that have to add up • Kakuro (Cross Sums) — a crossword written in numbers • Hashi (Bridges, Hashiwokakero) — join the islands into one network • Slitherlink (Loop the Loop) — one closed loop, drawn from the clues • Futoshiki — a Latin square with greater-than signs across it • Binairo (Takuzu, binary puzzle) — zeros and ones, never three in a row • Nurikabe (Islands and Walls) — islands of the right size, in one sea • Shikaku (Rectangles) — cut the grid into rectangles that match a number • Akari (Light Up) — light every square, and no lamp in another lamp's line • Masyu (Pearls) — a loop that turns on black pearls and runs through white ones • Norinori — one domino in every room • Heyawake — shaded rooms, and no white line running through more than two • Yajilin — a loop and a shading, on the same board Every type has a walkthrough that teaches its rules on a real board, and a rules card to open mid-board. The board • Drag to draw a line, drag to paint a wall — never one tap per segment • Pencil marks, cleared from the row and column for you if you want them • Undo and redo as far back as you like; every move saved as you make it • Mistakes shown your way: off, on Check, or as you make them. Nothing ever ends a puzzle • Pinch to zoom on the big grids, and a left-handed layout for the keypad • A colour-blind palette in which nothing is carried by colour alone • Grids from 4×4 to 20×20, and tiers named for the reasoning they need Hints that explain themselves A hint is the next real deduction the solver would make, written out in a sentence with the squares it is about lit up. Look, then the reason, then the move — never a revealed answer, and never something you could not have worked out. A puzzle a day One daily puzzle in every type, every day, at every difficulty. Your streak is counted quietly and never nagged about. A reminder is there if you want one, and it is an alarm on this device: nothing leaves it to make that happen. Made to be looked at Six board palettes, from warm paper through to full-contrast black on white. Thirteen drawn marks, one per type. A finished board reports your time and your previous best, and then stops: no confetti, no coins, no levels. Your progress, and your file Statistics per type, per size and per difficulty, with charts that answer whether you are getting faster, and a month view of everything you have solved. One backup file holds every puzzle, game, statistic and setting and reads back on any device — there is no account and no cloud copy, because there is no server anywhere in this app. One purchase, not a subscription Every puzzle type, every daily puzzle at every difficulty, and unlimited puzzles are free, and always will be. The unlock adds the rest: every grid size up to 20×20, the Hard and Expert tiers on every type, unlimited hints, all six themes, the whole daily archive, and the charts behind your times. One payment, held by your Apple Account and restored with one button on any device you sign into, including every puzzle type added after it. What this app will never do No ads. Not on opening, not between boards, not in exchange for a hint. No subscription, no coins, no energy, no lives. No account and no sign-in. Nothing that needs a network — puzzles are made on this device and your progress never leaves it. And nothing that ships free is ever moved behind the price. For anyone who does the puzzle page first: cross sums, bridges, loop the loop, binary puzzles, and the Japanese pencil puzzles that never got a good app.