# CrispSudoku — Classic, Killer, Thermo & more

> Classic, Killer, Thermo & more (iPhone/iPad app by Christian Strobele.)

- Source: https://appshunter.io/ios/app/crispsudoku/id6788990894 (this page in markdown: same URL + `.md`)
- Developer: [Christian Strobele](https://appshunter.io/developer/6788864041)
- Category: Games, Puzzle
- Price: Free
- Age rating: 4+
- Requires: iOS 15.0 · 20 MB
- Languages: American English
- Released: 2026-07-26
- Data updated: 2026-10-15

## What is CrispSudoku?

CrispSudoku is a polished, ad-free Sudoku game with real depth — five rule variants, six grid sizes, and a built-in tutor that explains how to solve every board.

PLAY YOUR WAY
• Five variants: Classic, Jigsaw (irregular regions), Sudoku-X (diagonals), Killer (summed cages) and Thermo (digits climb along each thermometer)
• Six grid sizes: 4×4, 6×6, 8×8, 9×9, 10×10 and 12×12
• Four difficulties, from Easy to Expert
• A new Daily Challenge every day — the same board for everyone

LEARN AS YOU PLAY
• "Explain the solve" walks through any board step by step, naming each technique (naked singles, hidden singles, locked candidates, X-wing and more)
• "Next logical step" hints tell you what to play next, and why
• Every puzzle gets an honest difficulty rating based on the hardest technique it actually requires

THOUGHTFUL TOUCHES
• Pencil-mark notes, unlimited undo, and live conflict highlighting
• A mistake limit that scales with difficulty
• Per-difficulty hint budgets, so hints stay meaningful
• Beautiful themes you unlock as you play
• Achievements, streaks and detailed statistics

PRIVATE BY DESIGN
• 100% offline — no account, no ads, no tracking, no data collection
• Every puzzle is guaranteed to have exactly one solution

CrispSudoku is free software, open source under the GNU AGPL-3.0.

## Is CrispSudoku safe?

Not enough ratings yet to assess CrispSudoku.

## Is CrispSudoku legit?

CrispSudoku appears legitimate, with a few gaps. The AppsHunter Legitimacy Score for CrispSudoku is 65 out of 100 points across 7 verification signals from App Store and developer data.


## Version history (last 4 releases)

### 1.4.0 — 2026-10-01

Thermo Sudoku — a new variant.

Digits climb from each thermometer's bulb to its tip. Every size up to 9×9, and most boards need no starting digits at all: the thermometers alone are enough to pin the grid down.

Also in this update:

• A much bigger board on small and folding phones. On a compact screen the grid had been taking about half the width — it now fills it.
• Landscape is a real layout instead of a squeeze: the controls sit beside the board rather than above and below it.
• Everything holds together at large accessibility text sizes, in English and German.
• Explain the solve fits the screen it is on, so the whole board and the explanation are visible at once.
• Pencil marks are readable again on 10×10 and 12×12 boards.
• Killer puzzles now draw their cages correctly in every build.
• Fixed a startup problem that could leave the game showing a blank screen.

### 1.0.3 — 2026-09-17

• A new look for the home screen, with a redesigned title and at-a-glance stats.
• 26 achievements across four tiers, with progress tracking and three new themes to unlock.
• Fixes digits being cut off or shrunk on the board and the number pad. Both now scale to the screen, so they stay centred and legible at any size or orientation.
• Fixes a crash that could occur when resuming a saved game.
• Smoother background animation, lighter on the battery.

### 1.0.1 — 2026-07-26

Fixes the on-screen number pad. On some screens the number buttons at the bottom of the board could appear oversized and get cut off, hiding the digits. The pad now scales to fit any screen so every number stays fully visible.

### 1.0 — 2026-07-17

No release notes.

## Apps similar to CrispSudoku

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| --- | --- | --- | --- |
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## More apps by Christian Strobele

- [CrisperWeaver](https://appshunter.io/ios/app/crisperweaver/id6789600762)
- [Word Universe](https://appshunter.io/ios/app/word-universe/id6790143931)
- [CrispAudio](https://appshunter.io/ios/app/crispaudio/id6791876962)
- [CometBeat](https://appshunter.io/ios/app/cometbeat/id6791962816)
- [Kerotakis](https://appshunter.io/ios/app/kerotakis/id6805214816)

All apps by Christian Strobele: https://appshunter.io/developer/6788864041

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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 2026-10-15.*