Metro Vancouver Transit Police have released OnDuty, a new smartphone app designed to allow commuters to silently report crime, track crime hotspots and check alerts and most wanted lists.

The OnDuty app is available for free on the Apple iTunes store for iPhones and iPads and the Google Play store for Android smartphones and tablets.

Initially announced as part of a global project tackling sexual assault on transit in April, the app is designed to allow transit riders to communicate directly with police if they feel threatened or witness any kind of crime.

"A very large proportion of transit users use their smartphone while travelling," said Chief Neil Dubord in a statement released on Thursday.

"Our OnDuty App provides them with a convenient and quick way to obtain Transit Police related information and as a result will contribute to the improvement of safety and security and comfort of the transit community."

Police say transit riders can use the app to discreetly to report non-emergencies directly to Transit Police dispatch without drawing attention to themselves or waiting until they get home to report crime.

The app will also provide alerts to keep riders informed about public safety concerns, missing persons or major service disruptions in real time, as well as track when the next bus will arrive.

Police emphasize the new app is for non-emergency reports only. In an emergency, call 911 as usual.

Users can find the app on the Apple or Android app stores by searching the phrase "transit police" or by following these links directly: OnDuty at the iTunes store and OnDuty at the Google Play store.