Old Nest App & new Gen Thermostats

[JazzRock]

I have six Nest Thermostats at home...each a different zone, of course, and approx 6-8 Nest smoke detectors. These were installed with the old Nest App which I still like using. I believe when new generation Thermostats do not work with the old app? Anyone with the old app have experience switching over to the Google Home app? 

I was thinking of upgrading my Thermostats but should I keep what I have and continue using the old Nest app as long as I can?

[Patrick_Caezza]

@JazzRock 

The new 4th Gen Learning thermostat and the Google Nest Thermostat (mirrored display) only work with the Google Home app.

The Thermostat E and 3rd Gen Learning Thermostat must be set up using the Nest App and once set up correctly can be controlled using the Google Home app.

The Nest Protect can only be used with the Nest App