I am a teacher and I'm excited about Securly! My observations: I usually visit students in their homes for after-school tutoring. The kids are generally preteens, too young to be exploring uncharted territories on their own, even if the parents had the "talk". In fact, almost all the parents I work with are very concerned about their kids coming across inappropriate content on web through computers and portable devices. They would like to delay this kind of "acquired worldly knowledge" as long as they can. I feel the same way as a parent myself. As to what age is appropriate, it is unique to each child and the family. Keep in mind that the decision making part of the brain does not really mature until late preteen age. All my students have special needs and parents need to be extra cautious.
I strongly hope that Securly finds its place in our homes and schools and the parents and schools must start taking proactive measures by thinking about new safeguards to put in place.