# MRU4u vs testo Smart

The clearest difference is in-app purchases: MRU4u at none against testo Smart's 5. MRU4u also leads on iOS requirement (15.0 vs 18.0). On price, review sentiment, update cadence and ads there is nothing between them.

Both are free to download. testo Smart sells 5 in-app purchases, starting at $6.99 per month. MRU4u asks for nothing beyond the download.

MRU4u ships an update every 5 weeks, testo Smart every 2 months. The most recent releases landed on October 4, 2026 and October 17, 2026 respectively.

## The numbers

| Metric | MRU4u | testo Smart |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[2.7 (167 ratings)](https://appshunter.io/ios/app/testo-smart/id1482139629/reviews)** |
| Number of ratings | — | **167** |
| Positive reviews | **16.7% of reviews** | 16.3% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 5 weeks** | Every 2 months |
| Monetization | **Free** | Free with in-app purchases |
| Size | 145 MB | 195 MB |
| Requires iOS | **15.0** | 18.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [MRU Messgeräte für Rauchgase und Umweltschutz GmbH](https://appshunter.io/developer/1110341400) | [Testo SE & Co. KGaA](https://appshunter.io/developer/966489178) |

## 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


### testo Smart

[App page](https://appshunter.io/ios/app/testo-smart/id1482139629)

This app supports measurements for refrigeration, HVAC, and heating systems. It also aids in food safety, frying oil quality, and indoor climate monitoring. Quickly interpret data, create digital reports with photos, and send them via email.

**Highlights:** All-in-one system measurements, Graphical display of measured values, Digital PDF/CSV measurement reports, Email report sharing, Leak test analysis, Automatic refrigerant charging, Indoor air quality monitoring

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

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Multi-site measurement | $6.99 | per month |
| Air balancing | $9.99 | per month |
| Multi-site measurement | $69.90 | per year |
| Air balancing | $99.90 | per year |
| Logging digital manifold | $44.99 | one-time |

**What reviewers like**

- 👍 Good app with some features
- 🚀 Great product
- 🚀 Useful app for measurements

**What reviewers complain about**

- 🐛 App won't connect
- 🐛 Connectivity issues
- 🐛 Unreliable connection
- 🐛 Forced updates
- 🐛 Laggy and unresponsive UI

**Reported bugs**

- App won't connect to devices
- Compatibility issues with newer iOS versions
- Frequent crashes and freezes
- Inability to save favorite refrigerants
- Measurement data not displaying properly

**Requested features**

- Add option to toggle Bluetooth discovery
- Improve Bluetooth range
- Add ability to customize colors and graphs
- Improve data export functionality
- Add option to name sensors


## Frequently asked questions

### Is MRU4u free?

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

### Is testo Smart free?

testo Smart is free to download, with in-app purchases available.

### Do MRU4u or testo Smart have ads?

Neither MRU4u nor testo Smart shows ads.

### Which is updated more often, MRU4u or testo Smart?

MRU4u ships an update every 5 weeks, and testo Smart every 2 months. Most recently, MRU4u was updated on October 4, 2026 and testo Smart on October 17, 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.*