Temtop 4+

Overall great. Frequent cannot connect to settings.
Bluetooth OK on device Bluetooth OK on cell phone inches away. The readings are great, live/accurate on app
HOWEVER... when you click on settings it keeps saying cannot connect. Have to close app and reopen and try again.

It's definitely worth 5-star feedback. I have my iPhone SE which is not a popular model as others. At first, there's a little problem with the graph in the App, so I sent an email to their customer service, and after 2 days, the little bug was fixed! I really appreciated their service as they consider all customers' comments. App interface is also well designed, I have two monitors in different cities, one is for my mom. Now I can "see" the air quality in her house, I believe it shortens our distance in some way.

I rely on this app and my Temtop meters/sensor devices to help me navigate addressing indoor air quality in my urban home. It's a vital part of my healthcare following a chemical exposure injury that leaves my nervous system vulnerable to VOCs and certain airborne particulates.

The developers have vastly improved this app in the past several months, providing easier connectivity and more features.

I have also had a lot of questions for the customer service and tech folks at Temtop over time, and they have been fantastically helpful and very personable.