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In the last century wartime warning systems were pretty low tech. From air raid sirens to emergency broadcast systems. But in the 21st century, your smartphone might just be your best warning tool.

In Lebanon, for example, as sectarian violence spills across Syria's border, apps are being developed for avoiding riots, car bombs, and even snipers. The military created "LAF Shield," which allows them to highlight danger zones for users to avoid. Users in turn can swipe to issue an SOS or report suspicious activity to the army.

Another app that uses crowd sourcing to pinpoint locations of protests, street fights and burning tires was downloaded 100,000 times in just one year.

And the goal of "Way to Safety," an app under development, is to be able to locate a gunman just using the smartphones in people's pockets. The app will record gunfire, identify the type of weapon being used and triangulate the exact location of the shooter, as long as several users are in the area.

Now we just need an app to get the world's warring factions to stop fighting and to make peace.