I took a course at my gliding club leading to a CAA radio operator's license a couple of years ago. It takes you through the main messages you need to know for proper use of a VHF radio in an aircraft.
I was able to use App Inventor blocks to tweak the audio output to conform to required standards - e.g. "three" is pronounced "tree". There's a place to enter emergency numbers, and a panic button that will send your GPS location and a Google maps location to an email address or as an SMS.