# Collatz Hailstone Link — A Collatz number-merge puzzle

> A Collatz number-merge puzzle (iPhone/iPad app by KwangHo Yun.)

- Source: https://appshunter.io/ios/app/collatz-hailstone-link/id6780455667 (this page in markdown: same URL + `.md`)
- Developer: [KwangHo Yun](https://appshunter.io/developer/1669492345)
- Category: Games, Puzzle
- Price: Free
- Age rating: 4+
- Requires: iOS 14.0 · 118 MB
- Languages: American English, Korean
- Released: 2026-06-21
- Data updated: 2026-08-15
- User reviews in markdown: https://appshunter.io/ios/app/collatz-hailstone-link/id6780455667/reviews.md

## What is Collatz Hailstone Link?

Collatz Hailstone Link — a relaxing number-merge puzzle built on one of math's most famous mysteries: the Collatz
  conjecture (the "3n+1" problem).

  Drag and merge numbered tiles, watch each sum bounce through the hailstone sequence, and chase the highest — or
  lowest — final number you can reach. Easy to learn in seconds, deep enough to keep you coming back for a better
  score.

  HOW TO PLAY
  • Drag one tile onto another (or tap one, then another) to merge them.
  • The two values are added, then the Collatz rule is applied to the sum:
     - Even sum → divide by 2 (the tile turns blue)
     - Odd sum → multiply by 3 and add 1 (the tile turns orange)
  • Chain the same color in a row to build a streak bonus.
  • Keep merging until a single tile remains. Push that last value as high — or as low — as you can!

  FEATURES
  • Pure one-finger gameplay — merge with a drag or a tap.
  • 7 board shapes: Square, Hexagon, Triangle, and four hybrid layouts.
  • Three-part scoring: turn points, streak bonuses, and a final bonus based on your last number.
  • Undo your recent moves to plan the perfect chain.
  • Records screen — sort your runs by score, max value, final value, and date.
  • Global online leaderboards — compete on both High Score and Final Max.
  • Light & Dark themes.
  • English & Korean language support.
  • Play offline, anywhere — no account required.

  WHY YOU'LL LOVE IT
  A quick puzzle for a coffee break, a brain teaser for math lovers, and a satisfying score-chaser for everyone in
  between. Every board is a fresh little puzzle in number theory — no two runs feel the same.

  Merge the numbers. Ride the hailstones. Beat your best.


## Version history (last 3 releases)

### 0.6.0 — 2026-07-05

* 2026/07/05 Version 0.6.0
- Bug fix

### 0.5.5 — 2026-06-23

* 2026/06/22 Version 0.5.5
- Bug fix

### 0.5.4 — 2026-06-22

No release notes.

## More apps by KwangHo Yun

- [1365 자원봉사 검색](https://appshunter.io/ios/app/1365/id1669492343)
- [캠퍼(Camper) : 고캠핑 검색](https://appshunter.io/ios/app/camper/id6445857006)
- [하루시작 : 날씨, 버스, 지하철](https://appshunter.io/ios/app/id6446796913)
- [Unforget! Day](https://appshunter.io/ios/app/unforget-day/id6755918740)
- [Pressure Gauge: Hold the Line](https://appshunter.io/ios/app/pressure-gauge-hold-the-line/id6779911849)

All apps by KwangHo Yun: https://appshunter.io/developer/1669492345

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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 2026-08-15.*