The Nest Learning Thermostat not only remembers temperature preferences, but it continually refines its schedule to ensure maximum comfort when users are home and to save energy when they are not. The Nest learns homeowners’ routines after one week, and then programs itself via sensors, algorithms, machine learning, and cloud computing, the maker says. A Wi-Fi connection allows users to check energy usage, set the temperature, and adjust the schedule online. Nest Labs. 855.469.6378.