Circle of 6

Circle of 6 is an app developed by Nancy Schwartzman and others to provide an easy tool to help keep yourself safe in a range of situations, or get help getting safe fast. It allows you to pick six contacts you know would likely be able to come and get you from somewhere (and it will show them exactly where you are and how to get there), call you to interrupt a bad situation, and a few subtle ways to alert those you choose to put in your circle if and when you are in trouble and need help.