# Rubicon vs Petroleum Engineering+

The clearest difference is ads: Petroleum Engineering+ at none against Rubicon's shown. Rubicon's advantage is update cadence (every 2 days vs monthly) and iOS requirement (13.0 vs 17.0). On price, in-app purchases and device support there is nothing between them.

Both are free to download. Rubicon sells 7 one-off in-app purchases and Petroleum Engineering+ sells 6 in-app purchases, starting at $9.99 per month. Whichever you choose, the download price is not the number that matters.

Rubicon ships an update every 2 days, Petroleum Engineering+ monthly. The most recent releases landed on September 9, 2026 and September 23, 2026 respectively.

## The numbers

| Metric | Rubicon | Petroleum Engineering+ |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/petroleum-engineering-plus/id6746214573/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | Yes | Yes |
| Ads | Yes | **No** |
| Update frequency | **Every 2 days** | Monthly |
| Monetization | — | Free with in-app purchases |
| Size | 698 MB | 18 MB |
| Requires iOS | **13.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [OneTwoPlay B.V.](https://appshunter.io/developer/1707024410) | [Forwa Elade Wunde](https://appshunter.io/developer/1685241344) |

## What reviewers say

### 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 |


### Petroleum Engineering+

[App page](https://appshunter.io/ios/app/petroleum-engineering-plus/id6746214573)

Master petroleum engineering concepts through engaging quizzes covering a wide range of topics from geology to production. Ideal for students and professionals seeking to enhance their knowledge and skills in the oil and gas industry.

**Highlights:** Comprehensive quiz coverage, Topics from geology to production, Boost knowledge and skills, Engaging learning experience, Suitable for students and professionals

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

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 1 Month | $9.99 | per month |
| 6 Months | $19.99 | per 6 months |
| 1 Year | $29.99 | per year |
| 1500 | $0.99 | one-time |
| 3500 | $1.99 | one-time |
| 9000 | $3.99 | one-time |


## Frequently asked questions

### Is Rubicon free?

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

### Is Petroleum Engineering+ free?

Petroleum Engineering+ is free to download, with in-app purchases available.

### Do Rubicon or Petroleum Engineering+ have ads?

Rubicon shows ads; Petroleum Engineering+ does not.

### Which is updated more often, Rubicon or Petroleum Engineering+?

Rubicon ships an update every 2 days, and Petroleum Engineering+ monthly. Most recently, Rubicon was updated on September 9, 2026 and Petroleum Engineering+ on September 23, 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.*