# Heat Engineer vs testo Smart

The clearest difference is review sentiment: Heat Engineer at 79% against testo Smart's 16%. Heat Engineer also leads on monetization model (free vs free with in-app purchases) and iOS requirement (15.6 vs 18.0). On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Heat Engineer sells 1 one-off in-app purchase and testo Smart sells 5 in-app purchases, starting at $6.99 per month. Whichever you choose, the download price is not the number that matters.

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on August 5, 2026 and September 20, 2026 respectively.

## The numbers

| Metric | Heat Engineer | 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 | **78.9% of reviews** | 16.3% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | Every 2 months |
| Monetization | **Free** | Free with in-app purchases |
| Size | 44 MB | 195 MB |
| Requires iOS | **15.6** | 18.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Heat Engineer Software Ltd](https://appshunter.io/developer/1461678894) | [Testo SE & Co. KGaA](https://appshunter.io/developer/966489178) |

## What reviewers say

### Heat Engineer

[App page](https://appshunter.io/ios/app/heat-engineer/id879510552)

This app assists heating engineers and surveyors in collecting property data for heating system installations. It supports heat loss reports for various technologies and includes tools for sound assessments and quick estimations. Data is automatically saved for later review and amendment.

**Highlights:** Heat loss survey for BS EN 12831, CIBSE, and MCS standards, MCS 020 sound assessment for Air Source Heat Pumps, Quick heat loss estimator tool, Automatic data saving and history for amendments, Room-by-room heat loss calculation, Photo capture for rooms and installation locations, Fuel comparisons and running cost calculations

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| MCS 020 PDF Report Token | $2.99 | one-time |


### 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 Heat Engineer free?

Heat Engineer is free to download, with in-app purchases available.

### Is testo Smart free?

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

### Do Heat Engineer or testo Smart have ads?

Neither Heat Engineer nor testo Smart shows ads.

### Which is updated more often, Heat Engineer or testo Smart?

Heat Engineer ships an update every 2 months, and testo Smart every 2 months. Most recently, Heat Engineer was updated on August 5, 2026 and testo Smart on September 20, 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.*