Good for setting up my Ham Radio SSB settings
make it work while screen is off
Does the job nicely.
I checked about dozen of applications on the market to get this one, which is comfortable to use. Rest of applicstions, I checked, are much more complicated to use, and totally non-intuitive.
Audio Tone Generator 20 - 20 000 Hz. Perfect for testing or pranking!
Frequency Sound Generator - waveform audio signal generator/ function generator