Thermostat came with my new heat pump/electric furnace last month (February 2019). Took me two days and numerous phone calls to Honeywell to get this thermostat on my wifi. Honeywell said it was my router. It's working now and I like the app.
We had non WiFi , before this. So installation was easy, all we had to do is take the old ones off and plug the new ones in and program them to our settings.
Frequently goes offline. Usually ok again after few minutes. However, was offline 3-4days and it wouldn't allow to reset wifi. Finally pulled it off back plate, let it set couple minutes, and reattached. Was ok after that.