"We are taking a very complex spy tool, adding a joke and making it something my kids are going to use a hundred times a day," Sell said.
Wickr lets people post pictures at leading social network Facebook but, in a twist, uses an old-time spy technique called "steganography."
Sell describes steganography as the art of hiding messages in plain sight. When Wickr pictures are posted to Facebook, what appears at the social network are adorable kitten photos instead of the personal images being shared.
Friends with Wickr apps installed can double-click on kitten pictures to see what was actually shared online. Those not in a person's Wickr circle, however, will only see baby cats. Even Facebook servers never see the real shared pictures, offering no opportunity to save copies, target ads, collect data or anything else, according to Sell.
WTF was inspired by Sell's eldest daughter. The teenager wanted to connect with friends on Facebook but met resistance from her mom, who has been a long-time organizer of the infamous Def Con hacker gathering that takes place annually in Las Vegas.