# Millimeter Pro vs Unit Plus Converter

The clearest difference is price: Unit Plus Converter at Free against Millimeter Pro's $3.99. Unit Plus Converter also leads on review sentiment (100% vs 58%) and rating (4.7 vs 4.4). On update cadence, ads, in-app purchases and monetization model there is nothing between them.

Unit Plus Converter is free to download; Millimeter Pro costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Unit Plus Converter holds the better App Store score, 4.7 against 4.4. That said, the two scores are not equally well evidenced: Unit Plus Converter has 564 ratings behind it against 108, so its average is the more settled of the two. Written reviews point the same way: 58% of Millimeter Pro's written reviews are positive against 100% of Unit Plus Converter's.

Millimeter Pro ships an update every 4 months, Unit Plus Converter every 5 months. The most recent releases landed on October 16, 2026 and October 14, 2026 respectively.

## The numbers

| Metric | Millimeter Pro | Unit Plus Converter |
| --- | --- | --- |
| Price | $3.99 | **Free** |
| Rating | [4.4 (108 ratings)](https://appshunter.io/ios/app/millimeter-pro-screen-ruler/id631810777/reviews) | **[4.7 (564 ratings)](https://appshunter.io/ios/app/unit-plus-converter/id1475355288/reviews)** |
| Number of ratings | 108 | **564** |
| Positive reviews | 57.9% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 4 months** | Every 5 months |
| Monetization | Free | Free |
| Size | 24 MB | 13 MB |
| Requires iOS | 15.0 | **11.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [VisTech.Projects LLC](https://appshunter.io/developer/620969851) | [Harjot Singh](https://appshunter.io/developer/1084273258) |

## What reviewers say

### Millimeter Pro

[App page](https://appshunter.io/ios/app/millimeter-pro-screen-ruler/id631810777)

This app transforms your device into a versatile measuring tool. It allows for precise measurements of length, area, diameter, and angles using the touchscreen. Easily split objects into equal parts and switch between millimeters and inches for your convenience.

**Highlights:** Touchscreen ruler and tape measure, Measure length, area, diameter, and angles, Split objects into equal parts, Supports millimeters and inches, Estimate radius, Thread pitch gauge

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

**In-app purchases:** none


### Unit Plus Converter

[App page](https://appshunter.io/ios/app/unit-plus-converter/id1475355288)

Easily convert between numerous units and metrics with this intuitive application. It offers over 100 common conversion units across various categories, presented in a simple and elegant interface.

**Highlights:** Over 100 conversion units, Multiple categories, Area conversion, Data conversion, Length conversion, Temperature conversion, Weight-mass conversion

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

**In-app purchases:** none

**What reviewers like**

- 👍 Brilliantly designed
- 👍 Easy to use
- 👍 No annoying banner ads
- 👍 Simple and clear interface
- 👍 Clean design

**What reviewers complain about**

- 🐛 Accuracy concerns (mpg to l/100km)
- 🐛 Conversion accuracy may be an issue

**Requested features**

- Kilogram to stones/pounds conversion
- Fractions of an inch down to 1/32” as a choice for conversion to mm


## Frequently asked questions

### Is Millimeter Pro free?

Millimeter Pro costs $3.99, with no in-app purchases.

### Is Unit Plus Converter free?

Unit Plus Converter is free to download, with no in-app purchases.

### Which has better reviews, Millimeter Pro or Unit Plus Converter?

Unit Plus Converter is rated higher. Millimeter Pro averages 4.4 out of 5 from 108 ratings, while Unit Plus Converter averages 4.7 from 564 ratings.

### Do Millimeter Pro or Unit Plus Converter have ads?

Neither Millimeter Pro nor Unit Plus Converter shows ads.

### Which is updated more often, Millimeter Pro or Unit Plus Converter?

Millimeter Pro ships an update every 4 months, and Unit Plus Converter every 5 months. Most recently, Millimeter Pro was updated on October 16, 2026 and Unit Plus Converter on October 14, 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.*