LONE TREE, Colo. — Parents have one more thing to worry about when it comes to their kids. There’s a new app that turns Snapchat into Tinder for teenagers.

It’s called Yellow and a Lone Tree mom found it on her daughter’s cellphone.

“I started looking in the folder and found this app called Yellow, which looked really kind of harmless. It’s just this yellow square,” said the mom, who wanted to remain anonymous.

But Yellow made her see red.

“Basically, it’s Tinder for kids. You match with various people, just like the dating app, you swipe left or right and become friends with them,” she said.

“I started to click on profiles, or whatever you call them, and there were some boys who asked not-so-nice things. My daughter didn’t know what it meant.”

It’s supposed to be for kids 17 years and older, but Yellow doesn’t prevent anyone with a Snapchat account to download it.

Our photographer opened a fake profile, saying he was 13 years old. Then, he uploaded a photo of a Minion.

And now, he was ready to swipe right to like a profile or swipe left to pass a profile.

“She is 12 years old. I don’t know why an app would be out there for a 12-year-old to match with a 17-year-old. It’s just terrifying,” the mom said.

Most of the profiles featured kids younger than the the required age of 17. And because of the anonymity, who knows if the profiles are legit.

“And these boys she friends with were supposedly 14. But they could have been 40, for all we know,” the mom said.

Plus, Snapchat lets kids’ so-called friends know their location at all times.

“That is why this is not a good idea for most kids to have,” said clinical psychologist and Metro State University of Denver professor Shawn Worthy.

He said the app widens a child’s limited social world beyond what is safe and healthy.

“What we are seeing is the (social) circle, at 13, widening to the world. And the reason the circle typically doesn’t developmentally widen like that, is because children 13, 14, 15 may not have the necessary cognitive skills to know how to keep themselves safe from the predators, craziness of the world,” he said.

Worthy also said kids don’t understand the ramifications of trading photos with others.

He recommends parents be very involved with their child’s app activities. He says know their passwords — and let them know you will check their phones at any time.