I haven’t heard it anywhere. Seems like a dumb idea, it dowsn’t bother at akk, and some people I know come close to passing out after a few seconds of high frequency noises I make on my pc.
Yup. And there may be more than just one in the App store. I came across it several months ago but since I don’t have any annoying teenagers loitering around my house, I never downloaded it to try out.
Does it really work ? I have no idea but they claim that it does, so who knows.
And last time I checked, it was free.