My siblings and I have the Nest app installed on our various iPhones so that we can monitor our mother in her nursing home with a Google Nest Cam IQIndoor camera.
While actively viewing, the app closes/crashes after 1-2 minutes. Re-launching the app, it closes again. There are no error messages. Between the three of us, we have deleted and re-installed and nothing fixes it. For me, it's an iPhone 8+ running Nest V22.214.171.124 and I keep my iPhone up-to-date. Today, iOS is 15.1
I also have the Nest app installed on my Samsung GS21 Ultra 5G for my Nest Video doorbell and the Nest app never closes/crashes.
I should point out, that my siblings and I are logged into the Nest iOS app under our mother's gmail account since I know of no way to access the Nest app on a single device using multiple Google accounts.