With your permission on Google's Nest permissions page, the app reads and controls the Nest thermostats you select: their names and rooms, temperature, humidity, mode, setpoints, and connection status. With your permission in iOS, it reads and controls the thermostats in your Apple Home.
Only to show your thermostats' status in the app and to send the changes you tap. Nothing is used for advertising, analytics, profiling, or any other purpose.
Google's access tokens are stored only on your iPhone, in the iOS Keychain. Thermostat readings are held in the app's memory while it's open. The app has no servers: data travels only between your iPhone and Google's or Apple's services.
The app doesn't sell, share, or transfer your data to anyone.
Thermostat Control's use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements.
You can remove the app's Google access at any time on Google's Nest permissions page or in your Google Account. To remove Apple Home access, open iPhone Settings, then Privacy & Security, then HomeKit. Deleting the app deletes its stored tokens.
Any change to this policy will be posted on this page with a new effective date.