Relying on friends and family to check up on you is so 2013. Now, you can program an app to track your whereabouts and make sure you're safe.
Kitestring is a simple, free and overprotective web app. First, you enter a list of emergency contact numbers to your account. Whenever you want the app to look out for you, you let it know that you're going on a trip and when you plan to return. At that time, the app will send you an SMS to check up on you, and you simply need to reply to confirm that you haven't died. If you don't respond, the app then alerts your emergency contacts.
If you're running late, you can notify the app and extend the length of your trip. Or if you get home ahead of schedule, you can check in early.
The idea certainly makes sense. But let's say, for example, that you're just taking a solo stroll late at night and you get mugged and someone steals your phone. If your attacker is somewhat tech-savvy, he or she could totally respond to the SMS pretending to be you and then nobody would know you were mugged and oh goodness the world is a scary place and maybe we need MORE overprotective apps.