A free program for Android, by Highway Radar.

Highway Radar is an app to help drivers be aware of road hazards, cameras, and speed traps. It connects to a server that collects and updates information from multiple sources. The app provides real-time and crowd-sourced alerts on potential risks on the road.

Crowd-sourced alerts: The app can connect to a server that collects and updates information from a crowd of people. It will show alerts on the map, and also issue audible voice warnings and a beep if it is available on your device.

Aircraft alerts: The app can also connect to the OpenSky network to get alerts about aircraft in the area.