To specify, this integration is supported on the ecobee3 lite, ecobee3 and ecobee4. With it, users can say, “Ok Google, make my home warmer,” among other commands to control their thermostats via a smartphone or Google Home.
As for how you set it up, head into the Home app (Google Home), then proceed into the Home Control settings menu. From here, add your ecobee device and link your accounts, then you’re good to go. It’s pretty painless and once you’re set up, you’ll be controlling ecobee with nothing but your voice.
Get on it.