# Engineer's Unit Converter vs ARCmaster

The clearest difference is in-app purchases: ARCmaster at none against Engineer's Unit Converter's 1. ARCmaster also leads on ads (none vs shown) and iOS requirement (15.0 vs 18.0). On price, update cadence and device support there is nothing between them.

Both are free to download. Engineer's Unit Converter sells 1 one-off in-app purchase. ARCmaster asks for nothing beyond the download.

Engineer's Unit Converter ships an update monthly, ARCmaster every 3 weeks. The most recent releases landed on October 15, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | Engineer's Unit Converter | ARCmaster |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Monthly | **Every 3 weeks** |
| Size | 7 MB | 30 MB |
| Requires iOS | 18.0 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Jose Gerardo Palma Duran](https://appshunter.io/developer/1873843788) | [Anh Thu Duong](https://appshunter.io/developer/1887275689) |

## What reviewers say

### Engineer's Unit Converter

[App page](https://appshunter.io/ios/app/engineers-unit-converter/id6758744042)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove Ads | $0.99 | one-time |


### ARCmaster

[App page](https://appshunter.io/ios/app/arcmaster-geometry-calculator/id6761011090)

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

**In-app purchases:** none


## Frequently asked questions

### Is Engineer's Unit Converter free?

Engineer's Unit Converter is free to download, with in-app purchases available.

### Is ARCmaster free?

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

### Do Engineer's Unit Converter or ARCmaster have ads?

Engineer's Unit Converter shows ads; ARCmaster does not.

### Which is updated more often, Engineer's Unit Converter or ARCmaster?

Engineer's Unit Converter ships an update monthly, and ARCmaster every 3 weeks. Most recently, Engineer's Unit Converter was updated on October 15, 2026 and ARCmaster on October 10, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*