E vs testo Smart
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
E
Control and monitor Gema OptiStar 4.0 electrostatic coating equipment in real time. View and adjust coating parameters, track productivity data, and manage equipment configuration. Includes automated firmware updates and diagnostic reporting.
- Real-time equipment control
- Coating parameter adjustment
- Productivity data monitoring
- Data export to PDF
- Maintenance countdown timers
- Automated firmware updates
- Diagnostic data retrieval
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With the useful functions of Gema‘s Electrostatic App you control and monitor your Gema OptiStar 4.0 equipment in real time: Application: All essential OptiStar 4.0 coating parameters are clearly visible on a Smart Device and can be directly adjusted and controlled. Designed for use with manual or automated Gema equipment. Line Management: View coating process productivity data on the device, and export the data in a PDF file. Important statistics and cost calculations from production are automatically generated. Maintenance countdown timers can easily be viewed at the touch of a button. Setup: With this function the configuration of the OptiStar 4.0 is defined. For automated equipment use, OptiStar 4.0 can be controlled as single device or in a group of control units. System information and diagnostic data are easily retrievable and can be sent via e-mail. The automated firmware update keeps your OptiStar 4.0 up to date.
testo Smart
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.
- 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
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- All in one: The testo Smart App supports you with measurements on refrigeration, air conditioning, and heating systems, as well as in ensuring the safety and quality of food and frying oil, and in monitoring indoor climate and storage conditions. - Fast: Graphically descriptive display of measured values, e.g. as a table, for quick interpretation of results. - Efficient: Create digital measurement reports including. photos as PDF/ CSV files on site and send them via e-mail. The testo Smart App is compatible with the following Bluetooth®-enabled measuring instruments from Testo: - Thermal imager testo 860i for smartphones - All Testo Smart Probes - Digital manifolds testo 550s/557s/558s/550i/570s and testo 550/557 - Digital refrigerant scale testo 560i - Vacuum pump testo 565i - Flue gas analyzer testo 300/310 II/310 II EN - Vacuum gauge testo 552 - Clamp meter testo 770-3 - Volume flow hood testo 420 - Compact HVAC measuring instruments - Frying oil tester testo 270 BT - Temperature meter testo 110 Food - Dual purpose IR and penetration thermometer testo 104-IR BT - Data loggers 174 T BT & 174 H BT - Online data loggers testo 160, testo 162 & testo 164 GW Applications with the testo Smart App Refrigeration systems, air conditioning systems and heat pumps, heating systems, indoor air quality: - Leak test: Recording and analysis of the pressure drop curve. - Superheat and subcooling: Automatic determination of condensation and evaporation temperature and calculation of superheat / subcooling. - Target superheat: Automatic calculation of target superheat - Automatic refrigerant charging by weight, by superheat, by subcooling, and by target superheat - Vacuum measurement: Graphical progress display of the measurement with indication of start and differential value Indoor climate monitoring: - Indoor air quality: automatic calculation of the dew point and wet-bulb temperature - Temperature, humidity, lux, UV, pressure, CO2: the right data logger for every application – from a single solution to an online monitoring system" Ventilation systems: - Volume flow: After the intuitive input of the duct cross-section, the app calculates the volume flow fully automatically. - Diffuser measurements: simple parameterisation of the diffuser (dimensions and geometry), comparison of the volume flows of several diffusers when setting up a ventilation system, continuous and multi-point average calculation. Heating systems: - Flue gas measurement: Second screen function in combination with testo 300 - Measurement of gas flow and static gas pressure: Also possible parallel to the flue gas measurement (delta P) - Measurement of flow and return temperatures (delta T) Thermography: - Determining Delta T on heating, refrigeration/air conditioning, and industrial systems - Detecting hot/cold spots - Assessing the risk of mold Food safety: Temperature Control Points (CP/CCP): - Seamless documentation of measured values to fulfill HACCP specifications - Individually definable limit values and measurement comments within the App for each measurement point - Reporting and data export for regulatory requirements and internal quality assurance Frying oil quality: - Seamless documentation of measured values as well as calibration and adjustment of the measurement instrument - Individually definable limit values and measurement comments within the App for each measurement point - Reporting and data export for regulatory requirements and internal quality assurance --------------------------------------------------------- Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://www.testo.com/en/company/privacy-policy-app
Screenshots
Verdict
The clearest difference is in-app purchases: E at none against testo Smart's 5. E also leads on iOS requirement (14.3 vs 18.0). testo Smart's advantage is update cadence (every 2 months vs every 9 months) and ratings volume (167 vs 7). On price, rating, ads and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. testo Smart sells 5 in-app purchases, starting at $6.99 per month. E asks for nothing beyond the download.
On the App Store both sit at effectively the same score — 2.7 for E against 2.7 for testo Smart. That said, the two scores are not equally well evidenced: testo Smart has 167 ratings behind it against 7, so its average is the more settled of the two. Written reviews are what separate them: 0% of E's written reviews are positive against 16% of testo Smart's.
E ships an update every 9 months, testo Smart every 2 months. The most recent releases landed on October 5, 2026 and October 13, 2026 respectively.
| Parameter | E | testo Smart |
|---|---|---|
| Price | Free | Free |
| Rating | 2.7 (7 ratings) | 2.7 (167 ratings) |
| Positive reviews | 0.0% of reviews | 16.3% of reviews — better |
| Number of ratings | 7 | 167 — better |
| Update frequency | Every 9 months | Every 2 months — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPod | iPhone, iPad |
| Requires iOS | 14.3 — better | 18.0 |
| Further details — not scored | ||
| Size | 108 MB | 195 MB |
| Age rating | 4+ | 4+ |
| Developer | Gema Switzerland GmbH | Testo SE & Co. KGaA |
Customer experience
E
testo Smart
Bugs and requests
E
Not enough reviews yet to summarise bugs or requests.
testo Smart
Reported bugs
5 issues- 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
7 requests- 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
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- Improve multi-probe support
- Integrate more features from physical devices
In-app purchases
E
No in-app purchases
testo Smart
- Multi-site measurement7 Days trial$6.991 Month
- Air balancing7 Days trial$9.991 Month
- Multi-site measurement$69.901 Year
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- Air balancing$99.901 Year
- Logging digital manifold$44.99









