AIBU to think that the Kooth app/site is a bit dodgy? It's a mental health support app backed by the NHS but has a peer-to-peer support option which seems to be miserable kids advising miserable kids. It also self advertises that it relies on trust for the membership so adults can easily sign up.
My year 6 child and their class have been directed to it during SATS and looking into it I feel very uncomfortable.