# Units Free vs Unit Converter For Engineers

The clearest difference is review sentiment: Unit Converter For Engineers at 100% against Units Free's 0%. Unit Converter For Engineers also leads on rating (5.0 vs 1.0) and update cadence (every 9 days vs every 5 months). Units Free's advantage is iOS requirement (5.1.1 vs 16.2). On price, ads, in-app purchases and monetization model there is nothing between them.

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

Unit Converter For Engineers holds the better App Store score, 5.0 against 1.0. Both are backed by a comparable volume of ratings — 1 and 3 respectively. Written reviews point the same way: 0% of Units Free's written reviews are positive against 100% of Unit Converter For Engineers's.

Units Free ships an update every 5 months, Unit Converter For Engineers every 9 days. The most recent releases landed on November 6, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | Units Free | Unit Converter For Engineers |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [1.0 (1 ratings)](https://appshunter.io/ios/app/units-free/id510615778/reviews) | **[5.0 (3 ratings)](https://appshunter.io/ios/app/unit-converter-for-engineers/id6752224915/reviews)** |
| Number of ratings | 1 | **3** |
| Positive reviews | 0.0% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 9 days** |
| Monetization | Free with in-app purchases | Freemium |
| Size | 3 MB | 5 MB |
| Requires iOS | **5.1.1** | 16.2 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 17+ |
| Developer | [Piet Jonas](https://appshunter.io/developer/288060167) | [Amanuel Abebaw](https://appshunter.io/developer/1766393564) |

## What reviewers say

### Units Free

[App page](https://appshunter.io/ios/app/units-free/id510615778)

Easily convert between various units across multiple categories like length, temperature, and weight. Access past conversions through a history list and send calculations via email. This free version offers core functionality with an option to upgrade for full category access.

**Highlights:** Multiple unit categories (length, temp, weight, etc.), Metric and imperial system support, Conversion history list, Send calculations via email, iPad multitasking support

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Units Free Upgrade | $0.99 | one-time |


### 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 |


## Frequently asked questions

### Is Units Free free?

Units Free is free to download, with in-app purchases available.

### Is Unit Converter For Engineers free?

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

### Which has better reviews, Units Free or Unit Converter For Engineers?

Unit Converter For Engineers is rated higher. Units Free averages 1.0 out of 5 from 1 ratings, while Unit Converter For Engineers averages 5.0 from 3 ratings.

### Do Units Free or Unit Converter For Engineers have ads?

Neither Units Free nor Unit Converter For Engineers shows ads.

### Which is updated more often, Units Free or Unit Converter For Engineers?

Units Free ships an update every 5 months, and Unit Converter For Engineers every 9 days. Most recently, Units Free was updated on November 6, 2026 and Unit Converter For Engineers on October 30, 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.*