# StemFox Scientific Calculator vs ResToolbox3

The clearest difference is in-app purchases: ResToolbox3 at none against StemFox Scientific Calculator's 6. ResToolbox3 also leads on update cadence (every 6 days vs every 3 months). StemFox Scientific Calculator's advantage is ratings volume (11 vs 2). On price, rating, 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. ResToolbox3 asks for nothing beyond the download.

ResToolbox3 holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: StemFox Scientific Calculator has 11 ratings behind it against 2, so its average is the more settled of the two.

StemFox Scientific Calculator ships an update every 3 months, ResToolbox3 every 6 days. The most recent releases landed on October 25, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | StemFox Scientific Calculator | ResToolbox3 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.8 (11 ratings)](https://appshunter.io/ios/app/stemfox-scientific-calculator/id1411592118/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/restoolbox3/id6759464322/reviews)** |
| Number of ratings | **11** | 2 |
| Positive reviews | 90.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 6 days** |
| Monetization | Freemium | **Free** |
| Size | 24 MB | 25 MB |
| Requires iOS | 15 | 15.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Joshua Bryson](https://appshunter.io/developer/1367675392) | [MobileReservoir](https://appshunter.io/developer/497057811) |

## 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 |


### ResToolbox3

[App page](https://appshunter.io/ios/app/restoolbox3/id6759464322)

This petroleum engineering calculator provides rapid answers for engineers in the field or office. It offers comprehensive tools for fluid properties, gas hydrate prediction, nodal analysis, production forecasting, volumetrics, and well testing, all accessible offline.

**Highlights:** Fluid properties (PVT) analysis, Gas hydrate prediction, Nodal analysis for wells, Production forecasting, Volumetric calculations, Well test analysis, Offline functionality

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

**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 ResToolbox3 free?

ResToolbox3 is free to download, with no in-app purchases.

### Which has better reviews, StemFox Scientific Calculator or ResToolbox3?

ResToolbox3 is rated higher. StemFox Scientific Calculator averages 4.8 out of 5 from 11 ratings, while ResToolbox3 averages 5.0 from 2 ratings.

### Do StemFox Scientific Calculator or ResToolbox3 have ads?

Neither StemFox Scientific Calculator nor ResToolbox3 shows ads.

### Which is updated more often, StemFox Scientific Calculator or ResToolbox3?

StemFox Scientific Calculator ships an update every 3 months, and ResToolbox3 every 6 days. Most recently, StemFox Scientific Calculator was updated on October 25, 2026 and ResToolbox3 on October 8, 2026.

---

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