I've seen a few QRP videos where the operator was able to see how far away his signal was able to be picked up by using a phone app. I don't know what this app is called or how it works, but it seems that it might be helpful for figuring out how well an antenna is functioning. Evidently there are receiving stations around the country that can automatically pick up call signs and send them to one's phone. Does anyone know what I'm talking about? If so, I'd like to learn more about this app.
Thanks,
Kim KG6WNG