At the last county IT conference for all Cornish teachers I attended the primary speaker spoke eloquently for an hour about the dangers that your children now face. The primary danger is not as you would expect exposure to unsuitable sites but rather the length of time that modern children spend using mobile devices.
I firmly agree that no primary school child should spend over two hours a day using a computer. That limit is often reached at school and so I will ensure that if I do set a computer based homework the video clip that needs to be viewed is a maximum length of around 5 minutes. Children should not be allowed tablets of phones in their bedrooms. Last year I found a child fast asleep in breaktime. It transpired that the parent had found their tablet still turned on in the bed with them the following morning.
At Churchtown we are outsourcing Internet security to Apple. Please see Mr Martin for details. For your home computer I would recommend software called K9 which is what I relied on at our old site. I have put a link to it below