The Prepared software turns smartphones into a "personal body cam" that can stream live to city 911 centers, so people can give authorities a real-time view of emergency situations. Prepared is now working with 12% of U.S. 911 centers, covering 80 million residents, including the cities of Nashville, Washington, D.C., Baltimore and Denver. It has raised $16.4 million from investors including First Round, M13 and 8VC.