Online safety
'The internet is amazing. Children can play, learn, create and connect - opening up a whole world of exciting possibilities. But with the digital world changing all the time, how can you make sure your child’s staying safe?' - NSPCC
Staying safe online (Safety Net Kids) 
Safer Internet Day 2018 Safer Internet Day 2018 will take place with the theme:
'Create, Connect and Share Respect: A better internet starts with you'.
YOTI app
Childline and the Internet Watch Foundation have come together to provide a service where children can request the removal of sexual images of themselves which have been shared online. As part of that process the child would be asked to provide a link to where the image is stored online, rather than send the image itself.
The child is also required to verify their identity and age and this is done through the YOTI app. YOTI will not store images of the child’s ID following the verification process. 
Below are details of online resources regarding this service:
There is a section which covers what you can do if you’ve lost control of a sexual image and refers to the YOTI app. 
There is the portal where you can report images and videos for take down and again refers to using the app to verify age.