Idea for app

My office building has only one toilet in the men's room.  Which becomes a problem when guys spend a lot of time there.  It appears that, as occupancy rises, this is happening more and more.  Which is why I think there should be, if not a webcam (at foot level, showing if there are shoes in there), then an app which we can have on our desktops telling us if the door to the stall is locked, or if the seat is warm, or whatever, because it's a bummer to walk out there and then find that somebody's in there working on the Great American Novel.