A Reno entrepreneur with a mission to protect women and children is trying to turn smartphones into virtual body guards.Arm Safety Button is an application and service for iPhone and Android-based smartphones that once triggered automatically sets off an alarm, takes a rapid series of photos of an assailant, projects a blinding light and places a call to 911.A woman, for example, walking alone in a parking lot at night can turn on the application, which then starts tracking the phone and its user's exact location via GPS. That's all the application does until it is turned off or activated …