It works like this: You tell Kitestring that you’re walking home alone, or in a dangerous place or situation, and you give it a time frame of when to check in on you. If you don’t reply back when it checks your status, it’ll alert your emergency contacts with a custom message you set up.

You can easily push back the check-in time if you’re taking longer in transit by texting it “10m” for ten more minutes, or turn it off entirely by telling it “ok,” once you get where you were going safely.

It’s a web-based service, so it works on any type of phone that has web browser: Android, iPhone, or BlackBerry. The easiest way to get it is to set up an account with your number and emergency contact information and then open the kitestring.io in your phone’s web browser and save the site to your home screen. That way you can access it when you need with the touch of a button.

The real advantage here is that Kitestring does the alerting for you without you having to punch anything in. I don’t know what it’s like to be in a compromising situation where you would need to alert people that your life is in danger, but I would imagine that when you’re in that kind of a situation you don’t have the time or the reflexes to enter a passcode into your iPhone and text or hit a special button to tell someone about it.