Zello is the highest rated push-to-talk app, connecting 150 Million users globally, empowering frontline workers, teams, and communities through instant and crystal-clear voice messaging. Because of its simplicity, Push-to-Talk is the easiest method of communication for teams encountering many different kinds of situations, from drivers out on delivery routes to hospitality workers communicating across a big hotel to ambulance drivers headed to the scene of an accident. PTT apps like Zello are more advanced and modern forms of the more traditional Push-to-Talk devices or Push to Talk phones.