# Diabolical Sudoku: Hard Logic — No guessing. Pure logic.

> No guessing. Pure logic. (iPhone/iPad app by kenta yamamoto.)

- Source: https://appshunter.io/ios/app/diabolical-sudoku-hard-logic/id6772833403 (this page in markdown: same URL + `.md`)
- Developer: [kenta yamamoto](https://appshunter.io/developer/1489320554)
- Category: Games, Education, Board, Puzzle
- Price: Free
- Age rating: 4+
- Requires: iOS 17.0 · 7 MB
- Languages: American English, Dutch, French (France), German (Germany), Hindi, Indonesian, Italian, Japanese, Korean, Polish and 9 more
- Released: 2026-05-28
- Data updated: 2026-08-30
- User reviews in markdown: https://appshunter.io/ios/app/diabolical-sudoku-hard-logic/id6772833403/reviews.md

## What is Diabolical Sudoku?

Diabolical Sudoku is a no-nonsense sudoku app built for one thing: hard puzzles.
If easy sudoku has stopped being fun, this is for you—every puzzle is chosen to need real techniques like X-Wing, XY-Wing, and Swordfish.

■ Three difficulties
・Hard … solvable by logic alone, with real bite
・Expert … advanced techniques required
・Diabolical … X-Wing / XY-Wing / Swordfish-class stumpers

■ Highlights
・Step-by-step explanations … stuck on a puzzle? See which technique cracks which cell, one move at a time
・One unique solution … no guessing, ever. Pure logic always gets you there
・Controls your way … pick your input order (digit-first or cell-first) and your memo style
・Pencil marks, auto-candidates, highlighting, and reset
・Auto-save, with clear status and solve times recorded
・No interruptions … no full-screen ads breaking your concentration

One good puzzle at a time. Chase that "I solved it!" feeling, again and again.


## Version history (last 5 releases)

### 1.3 — 2026-08-23

Made some small refinements. We'll keep improving the app so it stays a pleasure to play.

### 1.2 — 2026-06-07

Added a Contact option! You can now send feedback or report issues right from the Settings screen, without leaving the app. Thanks for playing!

### 1.1 — 2026-06-06

Now available in 19 languages—solve the same tough puzzles as sudoku fans worldwide.

### v1.0.4 — 2026-05-28

アプリのストア情報更新

### 1.0.3 — 2026-05-28

No release notes.

## More apps by kenta yamamoto

- [Buylis - Shopping List](https://appshunter.io/ios/app/buylis-shopping-list/id1665553308)
- [Tile Carpet Cycle](https://appshunter.io/ios/app/tile-carpet-cycle/id6772727568)
- [Infinite Math: Brain Puzzles](https://appshunter.io/ios/app/infinite-math-brain-puzzles/id6772833413)
- [Routin: Calm, gentle routines](https://appshunter.io/ios/app/routin-calm-gentle-routines/id6775340906)
- [Verdash for Vercel](https://appshunter.io/ios/app/verdash-for-vercel/id6777292026)

All apps by kenta yamamoto: https://appshunter.io/developer/1489320554

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-30.*