Nest is the most popular smart thermostat that is used in smart homes. The thermostat can be controlled from any device, or directly from the Nest thermostat. The device is 3.3 inches in diameter and costs $250 to buy.
The nest thermostat has a few systems in place to significantly cut down on energy usage in your home. One of these behaviours is to make Nest turn off the heating or cooling when no one is in the home. It can also be activated from your phone when you are not home. It also features an indicator marked as a leaf, that you can set the temperature to for optimized energy usage.
The device will learn to become familiar with what temperature and settings you set your thermostat to. This allows it to program itself to auto adjust within about a weeks time. It also integrates well with Amazon Alexa to enable voice commands.
The Nest product line also has products for indoor security cameras, outdoor security cameras and carbon monoxide detection.