Here is a link to NSPCC wesbite which gives great advice on how to keep children safe online.

http://www.nspcc.org.uk/preventing-abuse/keeping-children-safe/share-aware/

Thia is also very informative websites for keeping up to date with the latest APPs: https://www.commonsensemedia.org/

 This website will help with setting up parental filters: https://www.internetmatters.org/parental-controls/