Best Co2 Monitor 2 Apps

250+ iOS apps curated and reviewed

2.2 avg rating

20 free apps

Updated September 2026

Looking for free co2 monitor 2 apps? 20 of our 250+ tracked titles are free to download — no subscription, no trial. The rest are premium picks worth paying for.

Compare top Co2 Monitor 2 Apps (September 2026)

#	App	Price	Rating	Ads	In-App Purchases	Updated
1	C02 Monitor	Free	3.0★ (2)	No	No	May 2026
2	CO2 Monitor 2	Free	—	No	No	May 2026
3	Altos: Air analyzer, CO2 Check	Free	—	No	No	May 2026
4	CO2 on Watch & Lockscreen	Free	1.0★ (2)	No	Yes	May 2026
5	CO2 Filter Calc	Free	—	No	No	May 2026
6	CO2 Risk Calculator	Free	—	No	No	May 2026
7	Carbostar Sense	Free	—	No	No	Jun 2026
8	LogiCO2-Scout	Free	—	No	No	May 2026

Top Picks for Co2 Monitor 2

#1

C02 Monitor by ReFleX Wireless Inc.

requires a wireless CO2 sensor

Editor's Choice

📊 Productivity

3.0(2 ratings)

Free

C02 Monitor screenshot 1

This application displays real-time CO2 levels from compatible wireless sensors. It provides a remote view of indoor air quality, helping users monitor their environment.

#2

CO2 Monitor 2 by himpel

Strong Contender

0.0(0 ratings)

Free

CO2 Monitor 2 screenshot 1

CO2 Monitor 2 screenshot 2

CO2 Monitor 2 screenshot 3

CO2 Monitor 2 screenshot 4

CO2 Monitor 2 screenshot 5

#3

Altos: Air analyzer, CO2 Check by Woodenshark LLC

Wellness and Productivity App

Worth Considering

📊 Productivity

0.0(0 ratings)

Free

Altos: Air analyzer, CO2 Check screenshot 1

Altos: Air analyzer, CO2 Check screenshot 2

Altos: Air analyzer, CO2 Check screenshot 3

Altos: Air analyzer, CO2 Check screenshot 4

Altos: Air analyzer, CO2 Check screenshot 5

More Co2 Monitor 2 apps to explore

CO2 on Watch & Lockscreen

For Aranet4, Airvalent Inkbird

Monitor CO2 levels from compatible devices directly on your Apple Watch and iPhone Lock Screen. Receive smart alerts and view real-time air quality data with color-coded visuals for quick understanding.

Apple Watch complications with history graphiPhone Lock Screen widgetsCustomizable CO2 threshold alerts

free with in-app purchases

CO2 Filter Calc

CO2 Filter Calc

CO2 Filter Calc

by TOMCO2 Systems Company

CO2 Risk Calculator

CO2 Risk Calculator

CO2 Risk Calculator

by Logico2 International AB

Carbostar Sense

Carbostar Sense

Carbostar Sense

Smart CO₂ Air Monitor

by Logico2 International AB

Denbury CO2 Unit Converter

Denbury CO2 Unit Converter

Denbury CO2 Unit Converter

by Exxon Mobil Corporation

LogiCO2-Sniffer

LogiCO2-Sniffer

LogiCO2-Sniffer

by Logico2 International AB

AirSuite Monitor

AirSuite Monitor

AirSuite Monitor

Indoor environment monitoring

Denver CO2 Risk Calculator

Denver CO2 Risk Calculator

Denver CO2 Risk Calculator

by Logico2 International AB

by RATOC Systems, Inc.

Monitor environmental conditions with real-time data and historical graphs. This app visualizes temperature, humidity, and CO2 levels from a compatible Wi-Fi sensor.

Real-time data displayHistorical graph visualizationTemperature monitoring

IGC H₂-CO₂ Unit Conversion App

IGC H₂-CO₂ Unit Conversion App

IGC H₂-CO₂ Unit Conversion App

Industrial Gas Unit Conversion

💪 Health & Fitness

Air Lab – Air Quality Monitor

Air Lab – Air Quality Monitor

Air Lab – Air Quality Monitor

by Networked Artifacts

💪 Health & Fitness

Display SCD-41 CO2 readings.

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 readingsBluetooth sensor integrationSave readings with location

Open Gas Monitor

Open Gas Monitor

Open Gas Monitor

Monitor your gas consumption

Reduce Your CO2 – Help Planet!

Reduce Your CO2 – Help Planet!

Reduce Your CO2 – Help Planet!

by Slovak Eco Quality

FAQ about Co2 Monitor 2

What are the best co2 monitor 2 apps for iPhone?

C02 Monitor tops our co2 monitor 2 apps ranking as of September 2026, with a 3.0-star average from 2 App Store ratings, and it's free to download.

Are there free co2 monitor 2 apps for iPhone?

Yes — 20 of the top co2 monitor 2 apps we rank are free to download, including C02 Monitor and CO2 Monitor 2.

Does C02 Monitor have ads or in-app purchases?

C02 Monitor has no ads and has no in-app purchases, according to its App Store listing as of September 2026.

How many co2 monitor 2 apps are on the App Store?

We track 250+ co2 monitor 2 apps on the iOS App Store as of September 2026, ranked by rating, recency, and analysis of real user reviews.

What is C02 Monitor?

C02 Monitor is a free application that acts as a remote display for compatible wireless CO2 sensors. It allows you to view real-time CO2 levels from your sensor on your iPhone or iPad.

Does C02 Monitor require a CO2 sensor?

Yes, C02 Monitor requires a compatible wireless CO2 sensor to function. The app itself does not measure CO2 but rather displays data from a connected sensor.