# MRU4u vs FA 4xx App

The clearest difference is update cadence: MRU4u at every 5 weeks against FA 4xx App's every 34 months. FA 4xx App's advantage is iOS requirement (9.0 vs 15.0). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

MRU4u ships an update every 5 weeks, FA 4xx App every 34 months. The most recent releases landed on November 6, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | MRU4u | FA 4xx App |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 16.7% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 5 weeks** | Every 34 months |
| Monetization | Free | — |
| Size | 145 MB | 93 MB |
| Requires iOS | 15.0 | **9.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [MRU Messgeräte für Rauchgase und Umweltschutz GmbH](https://appshunter.io/developer/1110341400) | [Woehler Technik GmbH](https://appshunter.io/developer/959456679) |

## What reviewers say

### MRU4u

[App page](https://appshunter.io/ios/app/mru4u/id1110341401)

Control MRU Fluegas Monitoring Units remotely via Bluetooth. Transfer and store measured data on your smartphone or tablet, with options to export as CSV or email screenshots. View live data as text or charts, with customizable value displays.

**Highlights:** Bluetooth remote control, Live data display (text/chart), Customizable data views, Data storage on device, CSV data export, Email data screenshots

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

**In-app purchases:** none


### FA 4xx App

[App page](https://appshunter.io/ios/app/fa-4xx-app/id1466210879)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is MRU4u free?

MRU4u is free to download, with no in-app purchases.

### Is FA 4xx App free?

FA 4xx App is free to download, with no in-app purchases.

### Do MRU4u or FA 4xx App have ads?

Neither MRU4u nor FA 4xx App shows ads.

### Which is updated more often, MRU4u or FA 4xx App?

MRU4u ships an update every 5 weeks, and FA 4xx App every 34 months. Most recently, MRU4u was updated on November 6, 2026 and FA 4xx App on November 3, 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.*