Tuya Smart - Tuya Smart is a free to use Lifestyle Application by Tuya Inc.
Home-Assistant.io - Home Assistant is an open-source home automation platform running on Python 3.
Netatmo - Control your heating wherever you are
ioBroker - flexible and modular application for the IoT and Smarthome
Nest Thermostat (3rd gen) - A slimmer, sharper, sexier thermostat
openHAB - "empowering the smart home" - vendor and technology agnostic open source home automation