(CNN) -- Suicide prevention organization Samaritans has launched a free app that flags disturbing tweets and sends an alert to friends.
The app, Samaritans Radar, is currently available for Twitter users. Once downloaded, it sends an alert to your email address when a person you follow tweets phrases such as "help me," "tired of being alone," "hate myself" and "need someone to talk to."
Academic experts helped compile the words commonly used during difficult times, it said.
In addition to flagging tweets, the UK-based organization will help contact anyone you're concerned about 24/7.
"Samaritans Radar is in its infancy and won't get it right every time," the organization said in a statement Wednesday. "It's not good at sarcasm or jokes yet! But there's a way for you to give feedback on whether a Samaritans Radar alert was correct, so the service improves for everyone."
Every 40 seconds, someone in the world takes their own life, a global tally of more than 800,000 suicides a year, according to a United Nations report released last month.
Suicide kills more people annually than conflicts and natural catastrophes, the U.N. said.
The report analyzed suicide data from 172 countries and took a decade to compile.