Ecobee, a maker of smart thermostats for the home, just snagged $35 million in funding from Amazon’s Alexa Fund, Thomvest Ventures, and Relay Ventures. This is the largest single investment yet from the Alexa Fund, which Amazon set up to speed up the creation of software and hardware that works with its Alexa virtual assistant. Ecobee competes with the Google Nestsmart home thermostats, with one key difference: Its devices work with Amazon Alexa as a sort of hub.