# Square Stacker vs 21

The clearest difference is iOS requirement: Square Stacker at 13.0 against 21's 15.1. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Square Stacker ships an update every 3 days, 21 every 2 days. The most recent releases landed on June 1, 2026 and September 19, 2026 respectively.

## The numbers

| Metric | Square Stacker | 21 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (2 ratings)](https://appshunter.io/ios/app/square-stacker/id1342113409/reviews)** | — |
| Number of ratings | **2** | — |
| In-app purchases | No | No |
| Ads | Yes | Yes |
| Update frequency | Every 3 days | **Every 2 days** |
| Monetization | Ad-supported | — |
| Size | 33 MB | 39 MB |
| Requires iOS | **13.0** | 15.1 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Famobi GmbH](https://appshunter.io/developer/933760663) | [Chee Hoong Khor](https://appshunter.io/developer/1880679655) |

## What reviewers say

### Square Stacker

[App page](https://appshunter.io/ios/app/square-stacker/id1342113409)

This game blends Match 3 and Tic Tac Toe mechanics with colorful squares. Match three of the same color in a row, column, or stack to clear them. Strategize to achieve the highest score before the screen fills up.

**Highlights:** Match 3 and Tic Tac Toe mechanics, Color matching puzzles, Stacking gameplay, Strategy and planning, High score tracking, HD quality graphics

**Features:** macOS Compatibility

**In-app purchases:** none


### 21

[App page](https://appshunter.io/ios/app/21-twenty-one/id6759793279)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Square Stacker free?

Square Stacker is free to download, with no in-app purchases.

### Is 21 free?

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

### Do Square Stacker or 21 have ads?

Both Square Stacker and 21 show ads.

### Which is updated more often, Square Stacker or 21?

Square Stacker ships an update every 3 days, and 21 every 2 days. Most recently, Square Stacker was updated on June 1, 2026 and 21 on September 19, 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.*