A viewer sent me an email recently asking if I was familiar with the app Recolor. It's one of those apps that lets you color pictures by swiping or tapping your finger across the screen. I've reviewed several of these apps in the past but have not used Recolor. I knew that it was one of the most popular coloring book apps in Apple's App Store and the Google Play Store.

The viewer told me she had been using Recolor for some time and is a paying customer, but she was frustrated and very concerned by what she had been seeing recently from other Recolor users. Pornography, threats of violence and suicide, bullying and messages about sex. One screenshot she sent me was an actual photograph of two people having sex. She said this type of content was showing up regularly when she scrolled through the feed where other artists upload their latest creations.

When I checked the reviews of the Recolor app in both stores I found this had become a big problem as dozens of other Recolor fans were leaving similar comments and reviews.

I contacted Recolor by email and a spokesperson agreed to answering a few questions on a phone call. She told me they were aware of the growing problem and that if anyone reports a post, photo or user, moderators will review the post and if it violates the apps standards, it will be removed. Users can also be banned from the app for bad behavior.

The problem with waiting on a post to be reported is that the image can be viewable for hours or days or even weeks depending on if or when it's ever reported to moderators. So where does that leave this app?

Recolor is #21 in Apple's Entertainment category and it's used by over 4 million people every day. It has a loyal fan base and community. It's also an app with an age appropriate rating of 9 years old and up. While the vast majority of users encourage and collaborate with other artists, others are using the app's social network aspect to share porn and other disturbing images. We found one user who asks for people to subscribe to his posts for "juicy images."

The important thing for parents to note is that it isn't just the Recolor app. Any app with a social element that allows for users to communicate secretly with one another can be used by people wanting to share this type of material. Any app with a social element can also be used by sex predators to communicate with anyone using the app. Parents simply cannot assume any app, whether its for coloring, or sports or music or crafts, is safe to use by young children.