I'm only imagining this tool, I've done no research on it. In my imagination you may need to point the sound, you may need specialized speakers to get the right

I'm only imagining this tool, I've done no research on it. In my imagination you may need to point the sound, you may need specialized speakers to get the right frequency and duration for the click, and you might not want the clicker to be in your pocket / might not want to be holding your phone out of your pocket for long periods of time.