This thread inspired me to pull out the display and finally tinker with it - and then I realized how expensive the APIs are for this data - especially if trying to do a "constant updating" style approach like you'd want for this idea.
It makes sense you listen for the sound of a plane / wait for a button press before making the call!
Seems like this would be best done with a receiver and monitoring that directly and/or exchanging the radio logging for API access.
Another cool way to do this would be an ADS-B receiver on your roof. They're about $30-40, and when paired with a Raspberry Pi, a waterproof box, and free software[0] they work really well. Plus, you get a free subscription to a lot of flight tracking services like FR24.
