# StemFox Scientific Calculator vs mechanical design engine

The clearest difference is in-app purchases: mechanical design engine at none against StemFox Scientific Calculator's 6. mechanical design engine also leads on iOS requirement (13.0 vs 15). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. StemFox Scientific Calculator sells 6 in-app purchases, starting at $2.99 per month. mechanical design engine asks for nothing beyond the download.

StemFox Scientific Calculator ships an update every 3 months, mechanical design engine every 2 months. The most recent releases landed on October 25, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | StemFox Scientific Calculator | mechanical design engine |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (11 ratings)](https://appshunter.io/ios/app/stemfox-scientific-calculator/id1411592118/reviews)** | — |
| Number of ratings | **11** | — |
| Positive reviews | 90.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 2 months** |
| Monetization | Freemium | — |
| Size | 24 MB | 63 MB |
| Requires iOS | 15 | **13.0** |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Joshua Bryson](https://appshunter.io/developer/1367675392) | [gan dae choi](https://appshunter.io/developer/1574341439) |

## What reviewers say

### StemFox Scientific Calculator

[App page](https://appshunter.io/ios/app/stemfox-scientific-calculator/id1411592118)

Streamline complex STEM calculations with a powerful calculator, textbook equation solver, and comprehensive unit converter. Designed for engineers, it reduces busywork and improves accuracy for homework and technical tasks.

**Highlights:** Advanced scientific calculator with 80+ functions, Textbook equation solver for any variable, Searchable equation database by chapter, Fast table lookup with linear interpolation, Comprehensive unit converter with 300+ conversions, Copy and paste functionality for values and equations

**Features:** Vision Pro support

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly - Unlimited | $2.99 | per month |
| Yearly - Unlimited | $9.99 | per year |
| Donut | $0.99 | one-time |
| Drink | $2.99 | one-time |
| Taco | $4.99 | one-time |
| Pizza | $9.99 | one-time |


### mechanical design engine

[App page](https://appshunter.io/ios/app/mechanical-design-engine/id1574341437)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is StemFox Scientific Calculator free?

StemFox Scientific Calculator is free to download, with in-app purchases available.

### Is mechanical design engine free?

mechanical design engine is free to download, with no in-app purchases.

### Do StemFox Scientific Calculator or mechanical design engine have ads?

Neither StemFox Scientific Calculator nor mechanical design engine shows ads.

### Which is updated more often, StemFox Scientific Calculator or mechanical design engine?

StemFox Scientific Calculator ships an update every 3 months, and mechanical design engine every 2 months. Most recently, StemFox Scientific Calculator was updated on October 25, 2026 and mechanical design engine on October 11, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*