CO2 sensor vs Thermometer
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
CO2 sensor
Monitor CO2, temperature, and humidity levels in real-time using a Bluetooth sensor. Save readings with location data and sync them across Apple devices via iCloud. View historical data on a map.
- Real-time CO2, temperature, and humidity readings
- Bluetooth sensor integration
- Save readings with location
- iCloud sync across devices
- Map view of saved readings
- Open source code available
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Read CO2, temperature, and humidity from your Bluetooth Sensirion SCD-41 sensor in realtime. Save your readings with your current location and have it sync across your devices via iCloud. See previously saved readings with a map of the location that those readings were taken. Works across iPhone, iPad, and macOS devices. Open source code: https://github.com/sighmon/ios-ble-co2-sensor
Thermometer
Monitor indoor and outdoor temperatures in real time with detailed historical data and trend charts. Track temperatures from multiple locations simultaneously and access basic environmental data and converters.
- Real-time temperature tracking
- Historical data and trend charts
- Multi-location monitoring
- Environmental data
- Unit converters
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ThermoTrack is a smart temperature monitoring tool that lets you track indoor and outdoor temperatures in real time. It features detailed historical data and trend charts, allowing users to understand and respond to temperature changes easily. With multi-location support, you can monitor temperatures from different regions with a single app. Includes basic converters and extra environmental data.
Screenshots
Verdict
The clearest difference is rating: Thermometer at 4.5 against CO2 sensor's 3.4. Thermometer also leads on update cadence (monthly vs every 12 months) and ratings volume (394 vs 7). CO2 sensor's advantage is ads (none vs shown) and monetization model (free vs free with in-app purchases). On price, in-app purchases and iOS requirement 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. Neither carries in-app purchases, so what you see is what you pay.
Thermometer holds the better App Store score, 4.5 against 3.4. That said, the two scores are not equally well evidenced: Thermometer has 394 ratings behind it against 7, so its average is the more settled of the two.
CO2 sensor ships an update every 12 months, Thermometer monthly. The most recent releases landed on November 3, 2026 and October 30, 2026 respectively.
| Parameter | CO2 sensor | Thermometer |
|---|---|---|
| Price | Free | Free |
| Rating | 3.4 (7 ratings) | 4.5 (394 ratings) — better |
| Positive reviews | — | 65.4% of reviews |
| Number of ratings | 7 | 394 — better |
| Update frequency | Every 12 months | Monthly — better |
| Ads | No — better | Yes |
| In-app purchases | No | No |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad, iPod, Mac — better | iPhone |
| Requires iOS | 15.6 — better | 16.6 |
| Further details — not scored | ||
| Size | 0 MB | 5 MB |
| Age rating | 4+ | 4+ |
| Developer | sighmon | 梦楠 牛 |
Customer experience
CO2 sensor
Thermometer
Bugs and requests
CO2 sensor
Not enough reviews yet to summarise bugs or requests.
Thermometer
Reported bugs
2 issues- Gives incorrect temperature information
- Crashes or freezes
Requested features
1 request- Allow users to provide reviews without forcing 5-star ratings
In-app purchases
CO2 sensor
No in-app purchases
Thermometer
No in-app purchases
Questions
Is CO2 sensor free?
Is Thermometer free?
Which has better reviews, CO2 sensor or Thermometer?
Do CO2 sensor or Thermometer have ads?
Which is updated more often, CO2 sensor or Thermometer?
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