# MGS 400 vs Engineering Toolbox ET

The clearest difference is price: MGS 400 at Free against Engineering Toolbox ET's $1.99. MGS 400 also leads on rating (5.0 vs 4.0). Engineering Toolbox ET's advantage is ads (none vs shown). On ratings volume, in-app purchases, device support and iOS requirement there is nothing between them.

MGS 400 is free to download; Engineering Toolbox ET costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

MGS 400 holds the better App Store score, 5.0 against 4.0. Both are backed by a comparable volume of ratings — 1 and 1 respectively.

## The numbers

| Metric | MGS 400 | Engineering Toolbox ET |
| --- | --- | --- |
| Price | **Free** | $1.99 |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/mgs-400/id1441402354/reviews)** | [4.0 (1 ratings)](https://appshunter.io/ios/app/engineering-toolbox-et/id1570200621/reviews) |
| Number of ratings | 1 | 1 |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | Every 17 months | — |
| Monetization | **Ad-supported** | Paid |
| Size | 16 MB | 4 MB |
| Requires iOS | **14.0** | 14.3 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [MSA - The Safety Company](https://appshunter.io/developer/482957840) | [Ricardo Torres](https://appshunter.io/developer/1570200623) |

## What reviewers say

### MGS 400

[App page](https://appshunter.io/ios/app/mgs-400/id1441402354)

This app connects to compatible gas detectors via Bluetooth, simplifying configuration, maintenance, and calibration. It replaces the need for specialized tools and training, ensuring compliance with safety standards.

**Highlights:** Bluetooth connectivity, Device configuration, Alarm threshold adjustment, Maintenance testing, Zero/span calibration, Intuitive interface

**Features:** macOS Compatibility

**In-app purchases:** none


### Engineering Toolbox ET

[App page](https://appshunter.io/ios/app/engineering-toolbox-et/id1570200621)

This utility app provides quick access to essential electronic formulas and calculations. It helps users easily determine resistor color codes, capacitor codes, perform numeric base conversions, and calculate parallel resistors and LED resistors without needing to memorize complex equations.

**Highlights:** Resistor color code lookup, Capacitor code lookup, Numeric base conversion, Parallel resistors calculation, LED resistor calculation

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

**In-app purchases:** none


## Frequently asked questions

### Is MGS 400 free?

MGS 400 is free to download, with no in-app purchases.

### Is Engineering Toolbox ET free?

Engineering Toolbox ET costs $1.99, with no in-app purchases.

### Which has better reviews, MGS 400 or Engineering Toolbox ET?

MGS 400 is rated higher. MGS 400 averages 5.0 out of 5 from 1 ratings, while Engineering Toolbox ET averages 4.0 from 1 ratings.

### Do MGS 400 or Engineering Toolbox ET have ads?

MGS 400 shows ads; Engineering Toolbox ET does not.

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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.*