# Unit Converter For Engineers vs Hardness Conversion Master

The clearest difference is ads: Unit Converter For Engineers at none against Hardness Conversion Master's shown. Hardness Conversion Master's advantage is update cadence (every 3 days vs every 9 days). On price, in-app purchases, device support and iOS requirement there is nothing between them.

Both are free to download. Unit Converter For Engineers sells 2 in-app purchases, starting at $9.99 per year and Hardness Conversion Master sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Unit Converter For Engineers ships an update every 9 days, Hardness Conversion Master every 3 days. The most recent releases landed on September 18, 2026 and August 31, 2026 respectively.

## The numbers

| Metric | Unit Converter For Engineers | Hardness Conversion Master |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (3 ratings)](https://appshunter.io/ios/app/unit-converter-for-engineers/id6752224915/reviews)** | — |
| Number of ratings | **3** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 9 days | **Every 3 days** |
| Monetization | Freemium | — |
| Size | 5 MB | 259 MB |
| Requires iOS | **16.2** | 17.6 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 17+ | 4+ |
| Developer | [Amanuel Abebaw](https://appshunter.io/developer/1766393564) | [POYU WANG](https://appshunter.io/developer/1883764660) |

## What reviewers say

### Unit Converter For Engineers

[App page](https://appshunter.io/ios/app/unit-converter-for-engineers/id6752224915)

This app provides a comprehensive unit conversion tool specifically designed for engineers, offering specialized units not found in standard converters. It features offline functionality, fast search, and a clean interface, replacing the need for multiple reference materials.

**Highlights:** Specialized engineering units, Offline functionality, Fast search and instant conversion, Fraction input mode, Ad-free interface, Scientific notation support

**Features:** macOS Compatibility, Family Sharing

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Annual Subscription | $9.99 | per year |
| Lifetime Access | $29.99 | one-time |


### Hardness Conversion Master

[App page](https://appshunter.io/ios/app/hardness-conversion-master/id6760411989)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock Pro | $1.99 | one-time |


## Frequently asked questions

### Is Unit Converter For Engineers free?

Unit Converter For Engineers is free to download, with in-app purchases available.

### Is Hardness Conversion Master free?

Hardness Conversion Master is free to download, with in-app purchases available.

### Do Unit Converter For Engineers or Hardness Conversion Master have ads?

Hardness Conversion Master shows ads; Unit Converter For Engineers does not.

### Which is updated more often, Unit Converter For Engineers or Hardness Conversion Master?

Unit Converter For Engineers ships an update every 9 days, and Hardness Conversion Master every 3 days. Most recently, Unit Converter For Engineers was updated on September 18, 2026 and Hardness Conversion Master on August 31, 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.*