The new service has been launched by Marvin Humes of pop group JLS
A new online service for vulnerable children has been launched by the counselling charity ChildLine.
Children can use the site to e-mail about their concerns to the charity, chat to a counsellor online and support each other on message boards.
The extension of the charity's service has been provided by government funding and a NSPCC fund-raising campaign.
It comes as an NSPCC poll suggests one in three UK children feels some emotional distress most of the time.
In the online poll of 1,200 children aged 11 to 16, 32% said they felt sad, depressed, lonely, worried, stressed, scared or angry most of the time.
This increased to 49% among girls aged 14 to 16.
Meanwhile, 13% of children said they would "turn to no-one" for help and advice when in a bad mood, rising to 22% of 14 to 16-year-old boys.
The new site is being launched as part of a new NSPCC campaign called "How u feelin?" which is an attempt to reach out to more children.
It offers them tools to express their feelings through poems, pictures and emoticon-type "moodies" to keep track of their moods.
While online, children can watch videos, make badges or play games.
NSPCC chief executive Andrew Flanagan said: "Teenage years can be notoriously stressful for young people and the lucky ones have friends or parents to help them through their problems. But the scale of childhood distress in this poll is revealing.
"Hundreds of thousands of children phone ChildLine every year because they are so distressed and feel they have no-one else to turn to.
"Our new ChildLine online service is there for vulnerable children who would rather talk online than on the phone, giving them even more choice in how they seek help."