PicBlock is a utility that blocks all those webs that contain words that refer to porno or explicit sex, analyzing the words that it finds on these web pages (recognizing these words in dozens of languages) and allowing us to choose between 3 different awareness levels. It's also possible to input manually a series of websites to which access is blocked.
The program works in the background, so that nobody else knows that these restrictions exist, and to be able to edit its options it's necessary to know the password. Another feature is the possibility to establish a keyboard shortcut to activate or deactivate the block quickly.
If you want to block pornography from your browser in a simple way and totally free of charge, download PicBlock now.