Huffpopst has an article named:

5 Ways To Block Porn On Your Kids' Devices

But the funny thing is they have an ad for "PussyHats" on the bottom of the page, which means the page would be blocked if you turned on some of the porn blockers! Or some might block it because it uses the words "porn" and "sex" several times.

And of course, they never mention that despite all the software and hardware blocks you put in on your PCs and network, your kid is going to see porn at his friend's house. Blocking porn is about as effective as maintaining your kids belief in Santa Claus: Not much chance after 8 years old.