# Insterm vs Engineer's Unit Converter

The clearest difference is in-app purchases: Insterm at none against Engineer's Unit Converter's 1. Engineer's Unit Converter's advantage is update cadence (monthly vs every 5 months). On price, ads, device support and iOS requirement there is nothing between them.

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

Insterm ships an update every 5 months, Engineer's Unit Converter monthly. The most recent releases landed on October 6, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Insterm | Engineer's Unit Converter |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | Yes | Yes |
| Update frequency | Every 5 months | **Monthly** |
| Size | 10 MB | 7 MB |
| Requires iOS | **17.0** | 18.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Yusuke Mori](https://appshunter.io/developer/1662278979) | [Jose Gerardo Palma Duran](https://appshunter.io/developer/1873843788) |

## What reviewers say

### Insterm

[App page](https://appshunter.io/ios/app/insterm/id6742595334)

**Features:** macOS Compatibility

**In-app purchases:** none


### 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 |


## Frequently asked questions

### Is Insterm free?

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

### Is Engineer's Unit Converter free?

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

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

Both Insterm and Engineer's Unit Converter show ads.

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

Insterm ships an update every 5 months, and Engineer's Unit Converter monthly. Most recently, Insterm was updated on October 6, 2026 and Engineer's Unit Converter on October 24, 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.*