This is an audio spectrum analyser, acoustically coupled via the handset’s microphone.
Here, I am adjusting the frequency of a local oscillator (LO) in a transverter for a 1000 Hz beat note on a test signal.
I could do this by ear, but this is very quick and a lot more elegant. It saves mucking around with some PC-based program and getting the audio into the sound card.
Displays your current Maidenhead locator with 10 digit precision. It also computes bearing and distance to a target location using locator or latitude / longitude. Useful when aligning antennas in microwave activities. No network or fancy maps usage, so it can be used even in remote locations.
More apps to be added here in the future 🙂
For other Android apps that hams are using, have a look at this VKL Forum topic.