Personal anecdote getting an airthings that reminds me to open the window (along with a pushover api setup) has probably been the biggest productivity improvement in 10 years.
It's kinda worrying you need an app / appliance to remember to open the window. Rule of thumb is to have the windows open at least 10 minutes a day, every day.
You realize a lot of us live in places where that would be very expensive? Not to mention that the HVAC plants are usually not sized with that in mind.