You might have heard about Tinder. But are you familiar with Kik? How about Down?
Police warn that dating and anonymous messaging apps -- including some that are mysteries to parents -- are getting into the hands of children who are too young to use them.
That can expose children to content they aren't ready for, or worse.
Recently, reports surfaced that Nicole Madison Lovell, a 13-year-old Blacksburg girl, may have used the messaging app Kik to connect with an 18-year-old college student who is now accused in her murder.
And Prince George's police say a pornographic photo sent through the Kik app led them to investigate an elementary school choir director -- who is now accused of making child pornography on school grounds.
Many of these apps say they are not to be used by preteens. But Montgomery County, Maryland police said young people are drawn to them.
"These kids have no idea who they are talking to," said Rick Goodale, of Montgomery County Police. "And the dangers is these kids eventually may want to end up meeting somebody."
Here's a parent's guide to some of the newer apps:
Last year, a 14-year-old Fairfax boy was accused of using Kik to create a contest to generate child pornography.
And an anonymous man who claimed to be a convicted sex offender told WOOD TV, an NBC station in Michigan that the app is easily used by predators to contact children. "I can be whoever I want to be. I can get anybody I want. I can achieve my sexual glorification through this app," he said.
Whisper is a free app that lets users share secrets anonymously. Users post pictures with accompanying text and others comment in reply; there are no profiles. The company says this anonymous model helps prevent cyberbullying because people can be honest about themselves, the company's CEO told Mashable.
But the app also has a private messaging service, which enables predators to attempt to contact teens. It's easier to find someone nearby, because the app allows users to see posts within a 25-mile radius.
Yik Yak is designed for people in a specific area. Similar to Whisper, users post messages, or "Yaks," similar to bulletin board messages. The app is anonymous and users see posts made within a 10-mile radius.
Schools are concerned about the potential for cyberbullying and threats. At least 11 college students across the U.S. were charged for making threats on the app during the fall 2014 semester, reported CBC News in Canada. A former student at Michigan State University was sentenced to two years of probation Wednesday for making a school shooting threat on Yik Yak, the State News in Michigan reported.
Down, which used to be called "Bang with Friends," is a social media app that works with Facebook to identify friends on Facebook that say they are willing to hook up.
TeenSafe, a technology company that helps parents navigate new technology that their kids use, has called Down a "digital booty call."
This video chatting app can be used to connect users with anyone -- with no identity verification and no moderation. TeenSafe called it "perhaps the most dangerous" app on the TeenSafe 2016 App Blacklist.
Ask.fm is described as an app for "social Q&A." Users create profiles which let anyone ask them questions. The primary audience is ages 13 to 25, with half of registered users under the age of 18, the app's co-founder told CNET.
What Parents Can Do
OnGuardOnline is the federal government's website to help Americans stay safe online. A special section, Protect Kids Online, is a guide for parents, covering everything from child identity theft to cyberbullying.
Common Sense Media has guides for parents, complete with reviews, of popular apps and games.
HighTechDad compiled a brief guide for parents about the latest apps and their dangers to kids. Deleting and blocking apps will only do so much; he advises having conversations with your kids and making sure they know how to be safe online.