To protect yourself from a pornographic invasion of your home, you can use 'opendns' (free of charge) at the router level in your home, and not give admin access to the laptops/computers to anyone. You can set up user logins as regular users that cannot change the network settings (DNS) by default. Then, on 'opendns' you can select what kind of filters you want. This way you will filter out everything that "comes into your home" at the router level no matter what device(s) your house members use to connect.
The OpenDNS site is:https://www.opendns.com/home-internet-security/
It basically prevents accidental viewing of inappropriate material (you can select the categories that you deem inappropriate). It is not what they commonly call "filter," there is nothing to install, it's a configuration setting. It also helps somewhat against viruses, phishing, etc. You can also install additional filters, if you wish.
Please note: if you live in proximity to other open networks (as in an apartment) then the tablets/phones etc. can connect to a neighbor's open network.