The best smart thermostats of 2020 SEA802 do more than automate a fixed heating and cooling climate control schedule. These app-enabled smart home devices make it possible to adjust your thermostat from your smartphone whether you're on the couch, at the grocery store or on vacation-anywhere your smartphone is connected to a cellular or a Wi-Fi network. Many of these devices also work with Alexa, Google Assistant and Siri now too, giving you yet another way to adjust your thermostat settings with remote access.