A coloured dot/flame or similar could appear on the App itself each time a thermostat from any location calls for heat, then disappear after you have opened the App to check which thermostat/s are active.
This would quickly alert the user to the fact a thermostat had become active so that it could be turned off if there was no need for it to be on at that time.
I have to open my App several times a day to check there are no thermostats calling for heat unnecessarily as my house & granny flat has 16 thermostats and I am also about to add 2 new locations for my Airbnb properties which will have one stat each.
With this feature added I could just look at the App screen on my phone and would know immediately if any of the stats were active.
If it were possible to do this in the future I think it would be a fantastic improvement to the App & also a very environmentally friendly & cost saving feature.