ioBroker - flexible and modular application for the IoT and Smarthome
ecobee - The smarter wi-fi thermostat
Domoticz - Domoticz is a lightweight Home Automation System
Netatmo - Control your heating wherever you are
SEQUEmatic - SEQUEmatic lets you build sequences to link together your various smart devices.
Nest Thermostat (3rd gen) - A slimmer, sharper, sexier thermostat