INDIANAPOLIS - Most kids in middle school or high school have a smartphone these days, but do parents really know what apps are downloaded on those phones?
Parents of teens and young children may not be aware of some popular apps that are specifically designed to conceal images or to chat with strangers.
Police recently investigated a case at a local high school where they found more than a dozen students had used smartphone apps to pass nude photos.
SpyCalc is free in the app store. It looks just like a calculator -- and it is -- but it's also a vault to store photos.
It was one of the apps that was used by students at Avon High School to store naked photos of fellow classmates.
Brian Nugent is a detective with the Avon Police Department. He investigated December’s "sexting" scandal .
"What we're seeing here in Avon is something that is systemic of our society," Nugent said.
An app called Omegle costs 99 cents to download and promises chats with random strangers. The app states users need to be over 18, or 13 with parental consent.
Kik Messenger is another popular app. It's an instant messaging service that allows photos to be shared. Recent data showed there were nearly half a million downloads a month.
The app says users need to be 17 or older, but no proof of age is required. Anyone can simply click OK and download it.
"Technology's neutral, the apps themselves are neutral, but any community where children can come in contact with someone who wants to prey upon a child can have specific risks associated with it," Lt. Chuck Cohen with the Indiana State Police said.
Cohen said the apps themselves are not illegal.
Dave Fisher is an associate professor of mechanical engineering at Rose-Hulman Institute of Technology. He has developed apps for Apple.
"Ninety-nine point nine percent of the people out there are trying their best to make a good product, they're trying their best to be completely on the up and up," Fisher said
Apps like SpyCalc come with a user rating. SpyCalc is rated for those 9 and older, whereas Kik is rated for adults.
"When you submit your app for review, you list what you think you are and if Apple agrees with what you are, Apple lets you publish as that," Fisher said.
But if Apple disagrees, the app developer must resubmit until both parties agree on a rating.
Nugent believes the marketing for an app tells a lot about what the developer is after.
"My observation as a detective would be that they do know that they have a target audience that they're shooting for, whether or not it's in the images. They use the ease or difficulty of the software program itself, I do believe they have a target audience," Nugent said.
"It's not necessarily Google's job or Apple's job to keep it off the store because really you're giving the user, which in their mind is the high school person, right exactly what they want. They're agreeing to the permissions they know what it is," Fisher said.
Fisher said parents need to learn about capabilities like setting permissions on their kid's phone -- it could make all the difference in keeping dangerous apps off of a child's smartphone.
Follow Drew Smith on Twitter: @drewsmith1