# System Designer vs koe | 声を、世界のドキュメントに。

The clearest difference is in-app purchases: System Designer at none against koe | 声を、世界のドキュメントに。's 2. koe | 声を、世界のドキュメントに。's advantage is update cadence (every 6 days vs monthly). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. koe | 声を、世界のドキュメントに。 sells 2 in-app purchases, starting at $6.90 per month. System Designer asks for nothing beyond the download.

System Designer ships an update monthly, koe | 声を、世界のドキュメントに。 every 6 days. The most recent releases landed on November 2, 2026 and November 5, 2026 respectively.

## The numbers

| Metric | System Designer | koe | 声を、世界のドキュメントに。 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.4 (17 ratings)](https://appshunter.io/ios/app/system-designer/id1132983280/reviews)** | — |
| Number of ratings | **17** | — |
| Positive reviews | 77.8% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Monthly | **Every 6 days** |
| Monetization | Free | — |
| Size | 7 MB | 39 MB |
| Requires iOS | 15.6 | **15.1** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Erwan Carriou](https://appshunter.io/developer/1102494853) | [株式会社HARO](https://appshunter.io/developer/1868194947) |

## What reviewers say

### System Designer

[App page](https://appshunter.io/ios/app/system-designer/id1132983280)

Design complex systems using a low-code platform that leverages UML standards. Generate code skeletons and manage components graphically. Run and test your system with dynamic type checking.

**Highlights:** UML-based system modeling, Code skeleton generation, Graphical component creation, MSON format for model definition, Dynamic type checking, Cross-device synchronization via GitHub

**Features:** macOS Compatibility

**In-app purchases:** none


### koe | 声を、世界のドキュメントに。

[App page](https://appshunter.io/ios/app/koe/id6761331132)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Starter Plan | $6.90 | per month |
| Pro Plan | $34.90 | per month |


## Frequently asked questions

### Is System Designer free?

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

### Is koe | 声を、世界のドキュメントに。 free?

koe | 声を、世界のドキュメントに。 is free to download, with in-app purchases available.

### Do System Designer or koe | 声を、世界のドキュメントに。 have ads?

Neither System Designer nor koe | 声を、世界のドキュメントに。 shows ads.

### Which is updated more often, System Designer or koe | 声を、世界のドキュメントに。?

System Designer ships an update monthly, and koe | 声を、世界のドキュメントに。 every 6 days. Most recently, System Designer was updated on November 2, 2026 and koe | 声を、世界のドキュメントに。 on November 5, 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.*