# Exactly One: Logic Puzzle — One pebble. Every territory.

> One pebble. Every territory. (iPhone/iPad app by Amr Elsehemy.)

- Source: https://appshunter.io/ios/app/exactly-one-logic-puzzle/id6818081491 (this page in markdown: same URL + `.md`)
- Developer: [Amr Elsehemy](https://appshunter.io/developer/1675640788)
- Category: Games
- Price: Free
- Age rating: 4+
- Requires: iOS 17.0 · 4 MB
- Languages: American English
- Released: 2026-10-10
- Data updated: 2026-10-12
- User reviews in markdown: https://appshunter.io/ios/app/exactly-one-logic-puzzle/id6818081491/reviews.md

## What is Exactly One?

One pebble in every row. One in every column. One in every territory. No two may touch.

Exactly One is a polished, tactile logic puzzle built for short sessions and increasingly challenging boards. Each board is split into territories. Place pebbles so every row, column, and territory holds exactly one — and no two pebbles touch, not even diagonally.

The rules are simple and you learn them by playing. The first boards teach you in seconds; later boards demand real deduction.

EVERY PUZZLE HAS EXACTLY ONE SOLUTION
Every board is solver-verified to have a single valid answer, so you can always reason your way to it. No guessing required.

FEATURES
• 100 solver-verified boards, from gentle warm-ups to demanding grids
• A new daily challenge with streak tracking
• Instant feedback when pebbles conflict
• Unlimited undo and one-tap reset
• Hints that show you the next logical step without playing it for you
• Game Center achievements and a daily leaderboard
• Play fully offline — your progress is saved on your device

Tactile territories, satisfying pebbles, and a clean “aha” every time the board clicks into place.

From Knowlly Games.


## Version history (last 1 release)

### 1.0 — 2026-10-10

No release notes.

## More apps by Amr Elsehemy

- [Forge WallBall](https://appshunter.io/ios/app/forge-wallball/id6766298236)
- [Eidome](https://appshunter.io/ios/app/eidome/id6811835765)

All apps by Amr Elsehemy: https://appshunter.io/developer/1675640788

---

*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 2026-10-12.*