# Relay Flip:One Stroke of Color — Central & divided

> Central & divided (iPhone/iPad app by 振华 许.)

- Source: https://appshunter.io/ios/app/relay-flip/id1520989239 (this page in markdown: same URL + `.md`)
- Developer: [振华 许](https://appshunter.io/developer/1437340417)
- Category: Education, Entertainment
- Price: Free with in-app purchases
- Age rating: 12+
- Requires: iOS 15.6 · 17 MB
- Languages: American English, Chinese (Simplified, China)
- Released: 2020-07-03
- Data updated: 2026-01-10
- User reviews in markdown: https://appshunter.io/ios/app/relay-flip/id1520989239/reviews.md

## What is Relay Flip?

Two types of one stroke color puzzle. They are interesting and simple. But not easy.
  
1.Divided
   
The rectangle board have some disordered black and white blocks. The surrounded grey blocks is the transition area. The board is divided into some subregion. Just draw a stroke on the blocks of each subregion. The black and white of the blocks where the line passed are reversed. For the subregion, the color of each row should be the same. The end of the line is next to the start of the next subregion. Finally the color of  rows corresponding in all subregion must be the same.
Feature:
A. The size of board from 4*3 to 6*7.
B. The number of subregion from 1 to 4.
C. Global Ranking.
Rules:
A. The whole board include disordered black and white blocks, and the gray block is the transition area.
B. The whole board is divided into several continuous sub areas.
C. Draw a continuous line in each sub area. The black and white of the block where the line passes is reversed.
D. The color of each row in the sub area should be the same. The end of the previous sub area is next to the start of the next sub area.
E. The color of the row corresponding to all sub areas is the same.
  
2.Central
   
Including hexagon and square two kinds of board. There are some disordered black and white blocks on it. Draw a stroke from any position on the board, and the color of the block that the line passes through is reversed. When the color of each circle from the center outward is same (black or white) . The puzzle is solved.
Feature:
A. Two types of boards: Hexagon and square.
B. Board size from 3*3 to 11*11, from easy to difficult.
C. Simple interface and design.

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Remove ads | $0.99 | one-time |



## Version history (last 5 releases)

### 3.1 — 2026-01-09

Known bugs fixed.

### 3.0 — 2025-12-08

Update for new system.

### 2.1 — 2023-01-08

Fix minor bugs and improve performance.

### 2.0 — 2021-12-23

Fix minor bugs and improve performance.

### 1.9 — 2021-04-02

Optimize user experience.
Suggestion, ratings & reviews are welcome.

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## More apps by 振华 许

- [Brickmason](https://appshunter.io/ios/app/brickmason/id1437340418)
- [Tangram & Polyform Puzzle](https://appshunter.io/ios/app/tangram-and-polyform-puzzle/id1437352353)
- [Tangram & Polyform Pro](https://appshunter.io/ios/app/tangram-and-polyform-pro/id1437406341)
- [Brickmason - Pro](https://appshunter.io/ios/app/brickmason/id1437408076)
- [Overlap Elimination](https://appshunter.io/ios/app/overlap-elimination/id1438283033)
- [Tangram Plus](https://appshunter.io/ios/app/tangram-plus/id1443254526)

All apps by 振华 许: https://appshunter.io/developer/1437340417

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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 2026-01-10.*