Samaritans Radar was a free Twitter plug-in which used an algorithm to allow Twitter users to monitor  each others’ posts. It was launched on 29 October 2014 and suspended on 7 November 2014. It  was closed permanently on 10 March 2015.

Samaritans Radar used a list of keywords and phrases to identify tweets that indicated someone might  be struggling to cope.

It then sent an email alert to users who had signed up to monitor that account, flagging the tweet or  tweets in question and linking to guidance on the best way of reaching out and providing support.

The idea was to give Twitter users a second chance to see potentially worrying tweets from friends, in  case they missed them when they were originally posted.

Samaritans Radar was designed to provide an online safety net, after a 2013 study found an  association between rates of tweets per users determined to be at risk for suicide, and actual suicide  rates.