Yep, there's an app for that as i found out today. I live in a gated community and forgot my key card to scan to get in this morning. After sitting and waiting, hoping someone else would come, I was just staring at the gate when I saw a pole that extended up above the gate right at the edge. I followed it down, to some electrical piping that went to the main control box. At the top end was a small, projector type lens. I starting wondering what that little eye was for then, bored, and for the hell of it decide to break out the flashlight app which had a strobe setting. I turned the strobe on to medium or so and held it up to the eye. Sure enough, BEEP BEEP BEEP, and the gate opened. The eye is for emergency vehicles with their lights flashing to let them in. It worked better at night than during the day but I'm curious as to how many electronic gates have these 'eyes' for emergency vehicles.