Barely functional on a good day, usually takes about 3 or 4 tries to get the heater to ever start with this app or if you leave the thermostat on longer than 24 hours it flat out just stops working and won't even attempt to start heat or cooling, and during the summers you're lucky to get the app to ever turn on the AC without it adding a needless 10 - 30 minute delay for no good reason. Devs continue to attempt to delete my review, at this point i suggest buying literally any other thermostat