New Jersey's branch of the American Civil Liberties Union has taken its mission of policing the police to smartpones.

The ACLU is releasing an app called Police Tape that lets users secretly record police stops.

The ACLU of New Jersey's executive director, Deborah Jacobs, says it's a tool to make sure police are accountable.

Plenty of phones can record audio and video already. The new app lets them do it discretely with a stealth mode that hides the fact that recording is happening.

The app, first reported by The Star-Ledger, is launching for Android users. A version for iPhones is planned.

ACLU leaders say the only other branch with an app like this one is New York.

(Copyright 2012 by The Associated Press. All Rights Reserved.)