Civil liberties campaigners have unveiled a mobile phone app that will allow users to document police stops in New York and immediately submit them for review.

The New York Civil Liberties Union released the app following months of growing criticism surrounding the NYPD's practice of stopping and frisking hundreds of thousands of New Yorkers each year.

NYCLU leaders said the app, which is available on Android with an iPhone version out later this summer, would help the organization document the growing number of controversial police stops.

Last year close to 700,000 people were questioned on the city's streets. The vast majority were black or Latino and nearly nine out of ten had committed no crime. This year the department is on pace to shatter that record. Last month a federal judge granted class-action status to a lawsuit accusing the police of unconstitutional, racial profiling through stop and frisk.

The app is composed of three features: record, listen and watch. Recorded clips will be sent directly to the NYCLU, and users will be offered a brief survey allowing them to fill in the details of what they witnessed. The listen feature messages users when the app is activated by others and reports where the police stop is happening. The report feature allows users to detail police interactions they witnessed or experienced but were unable to film. The app also includes a "know your rights" element, intended to educate users.

"Today's release of the Stop and Frisk Watch adds another critical dimension to our quest for fair and just policing for all New Yorkers," said NYCLU executive director, Donna Lieberman at a press conference Wednesday.

Lieberman was joined by New York City council members Jumaane Williams, Leticia James and Melissa Mark-Viverito, as well as NAACP president Ben Jealous, National Action Network vice-president Michael Hardy and George Gresham, president of 1199 SEIU United Healthcare Workers East.

The app was developed by Jason Van Anden, who last year was responsible for the I'm Getting Arrested app, intended to help Occupy Wall Street protesters who found themselves being taken in by the police.

Van Anden – who has witnessed stop and frisks in his neighborhood–described his latest project as a "labor of love" that began in November.

Critics of stop-and-frisk say the practice has resulted in a two-tier a system of justice that favors white New Yorkers and disproportionately harms people of color. Mayor Michael Bloomberg and NYPD commissioner Ray Kelly have staunchly defended the practice, arguing it removes guns from the streets and saves lives.

On Monday, however, the two appeared to relax their hardline approach by supporting a proposal by New York state governor Andrew Cuomo to decriminalize possession of small amounts of marijuana, a charge that often follows stop-and-frisk encounters and overwhelmingly impacts minority youths.

A story published in the New York Post on Wednesday, before the press conference suggested the app could present a danger to users if the subject of a police stop reached in their pockets to pull out their phone. Lieberman stressed that the app is explicitly intended for witnesses of police stops, not subjects.