Just past sunrise on 69th Street, near a No. 7 subway stop in Queens, men in backpacks and work boots gather in groups, many on their cellphones.

They are workers at one of the largest day laborer stops in New York City, hoping to be hired. Most are undocumented immigrants who have reported being cheated by employers. In the fight against wage theft, their phones could soon become their biggest allies.

After three years of planning, an immigrant rights group in Jackson Heights is set to start a smartphone app for day laborers, a new digital tool with many uses: Workers will be able to rate employers (think Yelp or Uber), log their hours and wages, take pictures of job sites and help identify, down to the color and make of a car, employers with a history of withholding wages. They will also be able to send instant alerts to other workers. The advocacy group will safeguard the information and work with lawyers to negotiate payment.

Image Omar Trinidad, a construction worker, is the lead organizer who helped to develop the Jornalero app. Credit... Danny Ghitis for The New York Times

“It will change my life and my colleagues’ lives a good deal,” Omar Trinidad, a Mexican immigrant, said in Spanish through an interpreter. Mr. Trinidad is the lead organizer who helped develop the app.