Turning dark mode on in the Airthings app is very easy and you can update your app in two steps. To make sure you are using the correct app for your Airthings products, you can follow this link here to verify.

Go to "Settings" at the bottom right part of your screen and select "Themes"

Select "Dark (beta)" in the app to change its appearance to dark mode. Or, if you would like to have the theme based on your system default, you can select "System Default" in the app below to have this setting