This app will not work with the Honeywell RedLine series. A major drawback if you have one of their older systems that you want to control along with a newer T6 thermostat.
My only issue came when the thermostat lost connection to the wifi and I pushed something that turned it off. I had to figure out and unplug my thermostat to restart the wifi.
This is a massive pain to get working. It took many app updates over about 6 months before I was ever able to get it working with my wifi. Honeywell needs to invest in serious UX help soon.