# Sigma Domain vs OpenAgents Mobile

The clearest difference is in-app purchases: OpenAgents Mobile at none against Sigma Domain's 2. Sigma Domain's advantage is update cadence (every 2 days vs every 3 weeks). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Sigma Domain sells 2 in-app purchases, starting at $5.99 per month. OpenAgents Mobile asks for nothing beyond the download.

Sigma Domain ships an update every 2 days, OpenAgents Mobile every 3 weeks. The most recent releases landed on October 28, 2026 and October 29, 2026 respectively.

## The numbers

| Metric | Sigma Domain | OpenAgents Mobile |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 2 days** | Every 3 weeks |
| Size | 73 MB | 34 MB |
| Requires iOS | 16.6 | **15.0** |
| Devices | iPhone, iPad | iPhone, iPod |
| Age rating | 4+ | 17+ |
| Developer | [Sigma Domain](https://appshunter.io/developer/1876019749) | [ZHONGYUAN ZHU](https://appshunter.io/developer/1794669095) |

## What reviewers say

### Sigma Domain

[App page](https://appshunter.io/ios/app/sigma-domain/id6751211704)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Standard Monthly Sigma Domain | $5.99 | per month |
| Additional Usage - Sigma Domain | $9.99 | one-time |


### OpenAgents Mobile

[App page](https://appshunter.io/ios/app/openagents-mobile/id6805705527)

**In-app purchases:** none


## Frequently asked questions

### Is Sigma Domain free?

Sigma Domain is free to download, with in-app purchases available.

### Is OpenAgents Mobile free?

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

### Do Sigma Domain or OpenAgents Mobile have ads?

Neither Sigma Domain nor OpenAgents Mobile shows ads.

### Which is updated more often, Sigma Domain or OpenAgents Mobile?

Sigma Domain ships an update every 2 days, and OpenAgents Mobile every 3 weeks. Most recently, Sigma Domain was updated on October 28, 2026 and OpenAgents Mobile on October 29, 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.*