# AcuityAgent ONE vs C21 One21

The clearest difference is in-app purchases: C21 One21 at none against AcuityAgent ONE's 2. On price, update cadence, ads and device support there is nothing between them.

Both are free to download. AcuityAgent ONE sells 2 in-app purchases, starting at $0.99 per month. C21 One21 asks for nothing beyond the download.

AcuityAgent ONE ships an update every 5 months, C21 One21 every 3 months. The most recent releases landed on October 4, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | AcuityAgent ONE | C21 One21 |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 3 months** |
| Size | 357 MB | 69 MB |
| Requires iOS | **16.0** | 17.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 9+ | 4+ |
| Developer | [Acuity National Real Estate Solutions, LLC](https://appshunter.io/developer/1559165092) | [Century 21 Real Estate, LLC](https://appshunter.io/developer/371112830) |

## What reviewers say

### AcuityAgent ONE

[App page](https://appshunter.io/ios/app/acuityagent-one/id1559165090)

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly | $0.99 | per month |
| Yearly | $9.99 | per year |


### C21 One21

[App page](https://appshunter.io/ios/app/c21-one21/id6760855095)

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

**In-app purchases:** none


## Frequently asked questions

### Is AcuityAgent ONE free?

AcuityAgent ONE is free to download, with in-app purchases available.

### Is C21 One21 free?

C21 One21 is free to download, with no in-app purchases.

### Do AcuityAgent ONE or C21 One21 have ads?

Neither AcuityAgent ONE nor C21 One21 shows ads.

### Which is updated more often, AcuityAgent ONE or C21 One21?

AcuityAgent ONE ships an update every 5 months, and C21 One21 every 3 months. Most recently, AcuityAgent ONE was updated on October 4, 2026 and C21 One21 on October 7, 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.*