# Mechanical Engineering Book vs Petroleum Engineering+

The clearest difference is price: Petroleum Engineering+ at Free against Mechanical Engineering Book's $1.99. Petroleum Engineering+ also leads on update cadence (monthly vs every 11 months) and rating (5.0 vs 4.7). Mechanical Engineering Book's advantage is in-app purchases (none vs 6) and ratings volume (12 vs 1). On ads and device support there is nothing between them.

Petroleum Engineering+ is free to download; Mechanical Engineering Book costs $1.99 up front. Petroleum Engineering+ sells 6 in-app purchases, starting at $9.99 per month. Mechanical Engineering Book asks for nothing beyond the download.

Petroleum Engineering+ holds the better App Store score, 5.0 against 4.7. That said, the two scores are not equally well evidenced: Mechanical Engineering Book has 12 ratings behind it against 1, so its average is the more settled of the two.

Mechanical Engineering Book ships an update every 11 months, Petroleum Engineering+ monthly. The most recent releases landed on September 27, 2026 and September 23, 2026 respectively.

## The numbers

| Metric | Mechanical Engineering Book | Petroleum Engineering+ |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| Rating | [4.7 (12 ratings)](https://appshunter.io/ios/app/mechanical-engineering-book/id6448752936/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/petroleum-engineering-plus/id6746214573/reviews)** |
| Number of ratings | **12** | 1 |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 11 months | **Monthly** |
| Monetization | Paid | **Free with in-app purchases** |
| Size | 38 MB | 18 MB |
| Requires iOS | **10.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Haroon Khalil](https://appshunter.io/developer/1685448939) | [Forwa Elade Wunde](https://appshunter.io/developer/1685241344) |

## What reviewers say

### Mechanical Engineering Book

[App page](https://appshunter.io/ios/app/mechanical-engineering-book/id6448752936)

This app provides a comprehensive guide to mechanical engineering, covering fundamental concepts, key terms, and essential formulas. It's designed for students and professionals to deepen their understanding of machine mechanisms and engineering principles.

**Highlights:** Learn mechanical engineering principles, Understand machine mechanisms, Access engineering formulas and equations, Explore engineering facts, Covers thermodynamics, materials science, and more, Designed for professionals and students

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

**In-app purchases:** none


### 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 Mechanical Engineering Book free?

Mechanical Engineering Book costs $1.99, with no in-app purchases.

### Is Petroleum Engineering+ free?

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

### Which has better reviews, Mechanical Engineering Book or Petroleum Engineering+?

Petroleum Engineering+ is rated higher. Mechanical Engineering Book averages 4.7 out of 5 from 12 ratings, while Petroleum Engineering+ averages 5.0 from 1 ratings.

### Do Mechanical Engineering Book or Petroleum Engineering+ have ads?

Neither Mechanical Engineering Book nor Petroleum Engineering+ shows ads.

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

Mechanical Engineering Book ships an update every 11 months, and Petroleum Engineering+ monthly. Most recently, Mechanical Engineering Book was updated on September 27, 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.*