There's a dark world of human trafficking happening in the Bay area and across the country, where kids and adults are held captive for sex. But you may be able to help the victims, the next time you stay in a hotel room, just by snapping a few pictures.

“Without a doubt the most horrific thing I've gone through in my entire life,” says survivor Niki Cross. At just 15 years old, Cross was drugged and chained in an attic, sold and raped several times daily for nearly a year.

“If things could've ended earlier, there's things that I might not have had to endure,” Cross says.

The STAAR -- Stop The Abuse And Rescue -- Ministry founder now helps other victims and survivors in Pinellas County.

But you can help, too, with your smartphone.

Two sisters created the new app called TraffickCam.

It’s designed for any hotel guest staying anywhere around the country to help law enforcement fight human trafficking.

The app allows hotel guests to enter information about where they’re staying, including the hotel name and room number. They can also upload four pictures of their room. Investigators across the U.S. can then cross-reference those pictures with hotel photos of trafficking victims that typically appear online to see if there are any similarities using cutting-edge image analysis.

“The algorithm that is being run is actually matching data points in the clean photos that the public is uploading and comparing it to photos that are found online,” says Molly Hackett, creator of the app.

“Having an app like that will be a very beneficial and useful tool,” says Hillsborough County Sheriff's Office Detective Larry McKinnon. He says it could tip off investigators to a victim's location and save valuable time when lives are on the line.

“They can get that information back to law enforcement and maybe save someone's life,” McKinnon says.

So far the app has accumulated more than 1 million hotel photos. Developers say they have an 85% success rate of returning the correct location to investigators within the first 20 hotel options.

“Every day that they don't endure the abuse is one more day they are closer to healing,” says Cross.

The Traffick Cam app is free and does not save any personal information about your hotel stay.

Click here for more info to fight human trafficking