Chicago. You love it.

But you know it has another side. A dark side. And, well, you kind of love that, too.

Now you have a better way to keep tabs on it—and maybe have a little seedy fun in the process.

Introducing Police Radio Chicago, a new app that turns your iPhone into a police scanner—or what we like to call CSI: Chicago—letting you live out hard-boiled detective fantasies, available now.

Forget what you remember about those obsessive ham radio types sitting in their basements twiddling their knobs, desperately imputing frequencies for a few random squawks. This application—developed by the toughest University of Chicago economics doctoral candidate you're likely to meet—takes out the geekiness and adds in a little intrigue, in the form of an easy-to-read map that lights up with where the crime is going down.

That means when you're walking down the street and hear about a police chase in progress, you can glance at the map and know that your favorite den of iniquity still hasn't caught the attention of the fuzz. (Or you could go in and provide some backup.) Or imagine, if you will, cruising down Lake Shore Drive and hearing the police get a call about someone using their cell phone while driving.

Just casually put the iPhone under your seat.