# Project Chiron vs Rubicon

The clearest difference is in-app purchases: Project Chiron at none against Rubicon's 7. Project Chiron also leads on ads (none vs shown). Rubicon's advantage is update cadence (every 2 days vs every 8 days) and iOS requirement (13.0 vs 16.0). On price and device support there is nothing between them.

Both are free to download. Rubicon sells 7 one-off in-app purchases. Project Chiron asks for nothing beyond the download.

Project Chiron ships an update every 8 days, Rubicon every 2 days. The most recent releases landed on October 24, 2026 and October 4, 2026 respectively.

## The numbers

| Metric | Project Chiron | Rubicon |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 8 days | **Every 2 days** |
| Size | 171 MB | 698 MB |
| Requires iOS | 16.0 | **13.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [James Booth](https://appshunter.io/developer/1745107348) | [OneTwoPlay B.V.](https://appshunter.io/developer/1707024410) |

## What reviewers say

### Project Chiron

[App page](https://appshunter.io/ios/app/project-chiron/id6502346822)

**Features:** Vision Pro support

**In-app purchases:** none


### Rubicon

[App page](https://appshunter.io/ios/app/rubicon-math-games/id6743382440)

**Features:** macOS Compatibility

**In-app purchases (7)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 500 Gems | $4.99 | one-time |
| Battle Pass Premium | $4.99 | one-time |
| 1000 Gems | $9.99 | one-time |
| 1500 Gems | $14.99 | one-time |
| 2000 Gems | $19.99 | one-time |
| 2500 Gems | $24.99 | one-time |
| 3000 Gems | $29.99 | one-time |


## Frequently asked questions

### Is Project Chiron free?

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

### Is Rubicon free?

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

### Do Project Chiron or Rubicon have ads?

Rubicon shows ads; Project Chiron does not.

### Which is updated more often, Project Chiron or Rubicon?

Project Chiron ships an update every 8 days, and Rubicon every 2 days. Most recently, Project Chiron was updated on October 24, 2026 and Rubicon on October 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.*