# CSiUnits vs Mechanical Engineering Toolkit

The clearest difference is in-app purchases: CSiUnits at none against Mechanical Engineering Toolkit's 1. CSiUnits also leads on ads (none vs shown) and iOS requirement (9.0 vs 15.0). Mechanical Engineering Toolkit's advantage is update cadence (weekly vs monthly) and ratings volume (64 vs 4). On price, rating, review sentiment and device support there is nothing between them.

Both are free to download. Mechanical Engineering Toolkit sells 1 one-off in-app purchase. CSiUnits asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 4.8 for CSiUnits against 4.8 for Mechanical Engineering Toolkit. That said, the two scores are not equally well evidenced: Mechanical Engineering Toolkit has 64 ratings behind it against 4, so its average is the more settled of the two. Written reviews are what separate them: 50% of CSiUnits's written reviews are positive against 57% of Mechanical Engineering Toolkit's.

CSiUnits ships an update monthly, Mechanical Engineering Toolkit weekly. The most recent releases landed on September 17, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | CSiUnits | Mechanical Engineering Toolkit |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.8 (4 ratings)](https://appshunter.io/ios/app/csiunits/id1344138128/reviews) | [4.8 (64 ratings)](https://appshunter.io/ios/app/mechanical-engineering-toolkit/id1601099443/reviews) |
| Number of ratings | 4 | **64** |
| Positive reviews | 50.0% of reviews | **57.1% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Monthly | **Weekly** |
| Monetization | **Free** | Ad-supported |
| Size | 13 MB | 40 MB |
| Requires iOS | **9.0** | 15.0 |
| Devices | iPhone, iPad, iPod | **iPhone, iPad, iPod, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [Computers and Structures, Inc.](https://appshunter.io/developer/1119970032) | [APPS BAY LIMITED](https://appshunter.io/developer/1599035519) |

## What reviewers say

### CSiUnits

[App page](https://appshunter.io/ios/app/csiunits/id1344138128)

This application provides a comprehensive tool for converting units across various scientific disciplines and everyday needs. It offers over 70 conversion options, catering to professionals, students, and anyone requiring precise unit transformations.

**Highlights:** Multiple one-time conversion lists, Conversions for lifestyle and science, Over 70 conversion options, Numeric value input, Converted values to all possible units

**In-app purchases:** none


### Mechanical Engineering Toolkit

[App page](https://appshunter.io/ios/app/mechanical-engineering-toolkit/id1601099443)

This utility app provides a comprehensive collection of engineering equations and formulas for students and professionals. Easily perform calculations by selecting a formula and inputting variables, with detailed instructions and reference material included.

**Highlights:** Engineering equations and formulas, Mechanics of Material calculations, Theory of Elasticity formulas, Composite Material properties, Reference material, Variable input for calculations

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove Ads | $2.99 | one-time |


## Frequently asked questions

### Is CSiUnits free?

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

### Is Mechanical Engineering Toolkit free?

Mechanical Engineering Toolkit is free to download, with in-app purchases available.

### Which has better reviews, CSiUnits or Mechanical Engineering Toolkit?

CSiUnits and Mechanical Engineering Toolkit are both rated 4.8 out of 5 on the App Store, from 4 and 64 ratings respectively.

### Do CSiUnits or Mechanical Engineering Toolkit have ads?

Mechanical Engineering Toolkit shows ads; CSiUnits does not.

### Which is updated more often, CSiUnits or Mechanical Engineering Toolkit?

CSiUnits ships an update monthly, and Mechanical Engineering Toolkit weekly. Most recently, CSiUnits was updated on September 17, 2026 and Mechanical Engineering Toolkit on October 10, 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.*