There is an interesting app for Android and
iOS users called SafeTrek that you can use when in unfamiliar or
potentially dangerous areas. It was originally developed by
college students for college students and is extremely easy to
use.
Start the app and hold a finger on the onscreen button. If you
release the button and do not enter a 4 digit security code, local
police will be notified of your location, name, and emergency. The
price is $3 per month. LINK