Corentium Pro by Airthings 4+

I have invested close to $6000 for my business in these monitors and regretfully can not recommend them to another professional due to how poorly designed the app is.
The old app could have professional reports previewed, named, and emailed in under a minute. The new app can take upwards of 5-10 minutes per test. You have to connect to the monitor which then takes longer than old app. Finalize the report. Reconnect to the monitor again. Generate report and add unnecessary information that clutters the report then email to your client and yourself which is labeled as some randomized set of numbers symbols and letters. For those who like to keep records this in particular is very frustrating.
Considering switching monitors and can not recommend this app or the Corentium Pro monitors due to the fact you have to use this app to send reports with the Pro. Completely discontinuing the old app is poor customer service on AirThings and shows a complete disconnect from the professional community

There were some growing pains shifting to the new app, for sure. However they listened to users and made improvements. It is much better now.

Still a touch slower than the old version, but if you spend a bit of time updating the template once, you can make it as simple as the old version. However, now you have the capability of doing much more, including dynamic text where you can add explanation that is specific to your test situation. No need to go in and add text later. So, trading a bit of time up front for savings later on.

The new app and dashboard ecosystem also allows much better adherence with various state requirements that were simply not possible before, so those in states with licensing can be compliant with much less work overall.

I don't write many reviews but I believe it's worth the time to add to what other professionals are saying about the app. Hopefully it'll save someone the frustration of being forced to use it.
I have no complaints with the monitor itself but the app is absolutely frustrating and useless. The old app was great and easy to use without all the added time, connection issues, and extra useless info the user is forced to input. I could generate reports quickly and tailor the report to my client's interest with an easy to read report without the added junk. Like the others reviewing this app, I would love to continue using the device with the old app which was much faster and easier. Ultimately, I'm considering other options for my company in the future due to the frustration and lost time of the new app.