There is a tiny airport near my house for small personal planes. I see them through my office window above the tree line. I'd love to build a dashboard/screen on my desk to easily identify each aircraft. Ideally something more complicated than querying an existing api. Radar?
If the airplanes have ADSB transponder you can buy a cheap RTLSDR dongle and get data from there.
Another way, can be to record ATC conversations, translate them with an LLM and then track the airplane properly. This is harder and can be problematic from a legal standpoint (listening ATC is illegal in some countries)