A "panic button" smartphone app that can alert friends and family if you are in trouble or feel threatened has been released, its British developers say.

PanicMe, created by developer DataMe in consultation with local police forces, allows a user to set up a personalized response network of friends and family to be contacted when a panic alert is activated, The Daily Telegraph reported Friday.

A traffic light system offers three panic options -- green, amber or red -- depending on the seriousness of the event, and as many as 30 numbers in the phone's contact list can be selected for each panic option.

Red Alert signals a high risk situation with imminent danger, such as fear of being attacked, abducted or seriously ill and urgent help is required.

Amber is for a medium risk situation, where a user is in trouble and may come to harm if help doesn't come within half an hour to an hour.

Green denotes a low risk situation, possibly where a user is lost, separated from their group, or has suffered a vehicle breakdown.

GPS will give a user's panic network their exact location and help emergency responders locate them.

"With so many people these days having a mobile phone, apps such as PanicMe cannot only help to make those in need feel much safer but can also give peace of mind to those who care for them," former Deputy Chief Constable David Lindley said.

PanicMe is available for iPhone, Android and Windows smartphones.