A video of a 23-year-old woman using Periscope to broadcast herself live online allegedly while driving drunk quickly went viral Monday. But the story left some people asking, "What is Periscope?"

Periscope is a live-streaming app which Twitter bought earlier this year. The app allows you to broadcast on your mobile device what you are seeing to anyone in the world in real time.

Co-founder Kayvon Beykpour told CNNMoney he saw the app being used in a number of scenarios, from live events and protests to more personal moments, such as a baby's first steps.

But he probably never imagined this.

Whitney Beall, of Lakeland, was out drinking on Friday night and using her cellphone to broadcast what she was doing for the whole world to see on Periscope.

Lakeland police said two people watching the video feed called 911 to alert them of the situation. She was arrested on a DUI charge.

Police provided recordings of the video feed they downloaded from the Internet. On the videos, Beall could be heard many times announcing she was driving drunk.

Beall also stated she believed dozens of people were watching her on Periscope.

"Fifty-seven people. Oh, my God, I didn't know I'd get this many people," Beall could be heard saying on the video.

"She was out of it, and it was obvious by watching that live-streaming video how bad she was," Lakeland police Sgt. Gary Gross said.

At some point, two worried Periscope viewers called 911 to express their concerns.

"I just saw this girl on Periscope driving drunk," one of the callers said. "She doesn't know where she is."

How does Periscope Work?

The mechanics of Periscope are simple: Tap a button and start streaming whatever your camera lens sees. Anyone who follows you gets a notification to tune in. You can also host a private broadcast for a selected group of people — and they can watch in the app or any Web browser.

Some streamers are silent, while others prefer to narrate the action.

As you're watching someone stream, you can leave comments, which the broadcaster can see and respond to.