# Sudoku Classroom — Learn it, drill it, then play

> Learn it, drill it, then play (iPhone/iPad app by SANGHOON LEE.)

- Source: https://appshunter.io/ios/app/sudoku-classroom/id6811524512 (this page in markdown: same URL + `.md`)
- Developer: [SANGHOON LEE](https://appshunter.io/developer/6807384539)
- Category: Games, Puzzle
- Price: Free
- Age rating: 4+
- Requires: iOS 18.0 · 37 MB
- Languages: American English, German (Germany), Japanese, Korean, Chinese (Simplified, China), European Spanish
- Released: 2026-10-21
- Data updated: 2026-11-03

## What is Sudoku Classroom?

A sudoku app that teaches.

Without the techniques, a hard sudoku is just a wall. This app lays out three steps — Learn, Drill, Solve — across five course books.

■ Five books, twelve techniques

Book 1 Certain squares · Book 2 Block and line · Book 3 Sharing squares · Book 4 Rectangles and wings · Book 5 Chains.
From naked single through X-Wing, Swordfish, XY-Wing and simple colouring, twelve techniques are explained one step at a time on a real board.

■ Learn → Drill → Solve

• Learn — lessons on a live board, pointing at the cell that makes the deduction work
• Drill — one technique in isolation: find it, and the app grades you
• Solve — a puzzle whose last gate is exactly that technique

■ Hints that reason, not just reveal

Tap Hint and it does more than fill a square. It names the technique, highlights the cells the deduction rests on, and tells you why that digit has to go there.

■ The difficulty is the technique

All 10,000 puzzles were solved through and graded by the last technique needed to finish them. These are not labels we made up. Each puzzle was verified to have exactly one solution, and every clue layout is symmetric, so the board looks settled the moment you open it.

■ Tools that help you think

• Pencil notes — place a digit and the same candidate clears itself from the neighbours
• Undo — takes back exactly one move, no more
• Check — tells you how many of your digits are wrong, and nothing else
• 3 hearts — run out and the game simply carries on quietly, without scolding you

■ Your progress stays

Puzzles solved, time spent and score add up per book, and every single game is kept in a score history. A daily streak keeps you coming back for one puzzle a day.

■ Ads only when you ask

No banners, nothing that blocks the screen. A short video plays only when you tap to get more hints or to bring your hearts back.

■ Works offline

All 10,000 puzzles ship inside the app. iCloud keeps your iPhone and iPad in step — no account, no sign-in.

iPad is supported in both portrait and landscape.
Available in English, Korean, Japanese, Chinese (Simplified), German and Spanish.

## Is Sudoku Classroom safe?

Not enough ratings yet to assess Sudoku Classroom.

## Is Sudoku Classroom legit?

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


## Version history (last 2 releases)

### 1.0.1 — 2026-11-02

Stability and reliability improvements.

- Hearts now belong to your account instead of resetting with every puzzle. You get three when you first install, and the only way to earn more is the optional rewarded video. Running out never blocks play - only the red marking of wrong squares turns off.
- Finishing every puzzle in a book now tells you so, instead of the Play button doing nothing.
- The app is portrait only, on iPhone and iPad alike.
- Layout fixes: the already-solved screen now centres properly, and the More screen heading no longer clips in German or sits out of line on iPad.

### 1.0 — 2026-10-21

No release notes.

## More apps by SANGHOON LEE

- [Beoltteok Alarm](https://appshunter.io/ios/app/beoltteok-alarm/id6807384537)
- [Exchange Rates - All at Once](https://appshunter.io/ios/app/exchange-rates-all-at-once/id6809696623)
- [Journey Ledger](https://appshunter.io/ios/app/journey-ledger/id6814377365)
- [Chromibop](https://appshunter.io/ios/app/chromibop/id6820057777)
- [Gumlock: Password Manager](https://appshunter.io/ios/app/gumlock-password-manager/id6822549870)

All apps by SANGHOON LEE: https://appshunter.io/developer/6807384539

---

*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 2026-11-03.*