# Stack Sort vs Clue Formula

The clearest difference is in-app purchases: Stack Sort at none against Clue Formula's 2. Stack Sort also leads on ads (none vs shown) and iOS requirement (9.0 vs 17.0). On price, update cadence and device support there is nothing between them.

Both are free to download. Clue Formula sells 2 one-off in-app purchases. Stack Sort asks for nothing beyond the download.

Stack Sort ships an update every 5 days, Clue Formula every 4 days. The most recent releases landed on November 7, 2026 and November 4, 2026 respectively.

## The numbers

| Metric | Stack Sort | Clue Formula |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (4 ratings)](https://appshunter.io/ios/app/clue-formula/id1616776014/reviews)** |
| Number of ratings | — | **4** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 5 days | **Every 4 days** |
| Monetization | — | Free with in-app purchases |
| Size | 158 MB | 22 MB |
| Requires iOS | **9.0** | 17.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Mac |
| Age rating | 4+ | 4+ |
| Developer | [DEVGEIM](https://appshunter.io/developer/1462267626) | [x2line.com LLC](https://appshunter.io/developer/425135293) |

## What reviewers say

### Stack Sort

[App page](https://appshunter.io/ios/app/stack-sort/id1497846737)

**Features:** macOS Compatibility

**In-app purchases:** none


### Clue Formula

[App page](https://appshunter.io/ios/app/clue-formula/id1616776014)

Engage in a 3D Mahjong puzzle game featuring IQ-test style tiles. Match selectable pairs to clear levels, with increasing difficulty as you progress. Utilize hints and shuffles to aid your gameplay and compete on leaderboards.

**Highlights:** 3D Mahjong puzzle gameplay, IQ-test style tiles, Layered 3D levels, Hint and shuffle options, Leaderboard competition, VoiceOver accessibility

**Features:** Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Hint | $0.99 | one-time |
| Shuffle | $0.99 | one-time |


## Frequently asked questions

### Is Stack Sort free?

Stack Sort is free to download, with no in-app purchases.

### Is Clue Formula free?

Clue Formula is free to download, with in-app purchases available.

### Do Stack Sort or Clue Formula have ads?

Clue Formula shows ads; Stack Sort does not.

### Which is updated more often, Stack Sort or Clue Formula?

Stack Sort ships an update every 5 days, and Clue Formula every 4 days. Most recently, Stack Sort was updated on November 7, 2026 and Clue Formula on November 4, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*