A new smartphone app is helping young Iranians avoid Tehran's morality police, who have become notorious for harassing anyone whose dress or public behavior doesn't adhere to strict Islamic standards.

The app, called Gershad, uses crowdsourcing to identify the locations of Iran's morality police, known by their Persian name Gasht-e Ershad ("guidance patrol"). Ershad officers regularly patrol the streets of Tehran to identify men and women who violate Islamic code of conduct, and they have come under criticism for abusing their powers. Those found to be in violation — typically women who wear too much makeup, or the wrong type of hijab — can be thrown into the back of a van and detained. They're often let off with a warning or released after being lectured, though some have been fined or prosecuted.

Gershad helps Iranian women avoid police checkpoints by crowdsourcing their locations and displaying them on a map. Users who identify a checkpoint can anonymously mark it on the map to warn others, in much the same way that drivers flag traffic stops on the navigation app Waze. When users report a sighting, a small police icon appears on the map for other users to see. Since its release this week, Gershad has been downloaded more than 16,000 times from the Google Play store, and more than 1,500 reports have been filed on it. (It's only available on Android for now.)

Gershad's creators say they see the app as a form of "nonviolent resistance" to Iran's morality police, who sometimes deploy heavy-handed tactics. "We know how embarrassing, humiliating and at times frightening it can be to be stopped by Ershad," one of Gershad's creators said in an email. (The developers declined to disclose their identities for this article, citing concerns over government retaliation.)

The Gasht-e Ershad enjoy broad powers, and can stop people for a broad range of offenses — hugging someone of the opposite sex in public, for example, or exposing piercings and tattoos. Women are regularly targeted, though those in Iran's LGBT community can run into trouble as well, experts say. The officers travel in groups of four — two men, two women — and are frequently stationed outside of malls, restaurants, and other social hotspots. Experts say that for young Iranian urbanites, avoiding the Gasht, as they're known colloquially, has become a part of everyday life.

"I don't think there's anyone in Iran, anyone who's young, who has not been stopped by the Gasht for some reason or another," says Narges Erami, an assistant professor of anthropology at Yale University who has conducted extensive fieldwork in Iran. Erami says she was stopped by a patrol in Tehran a few years ago while traveling in a car with her cousins. The officers stopped the group because they were playing loud music, and briefly interrogated them before allowing them to continue. Erami says the interaction was far from combative, though others have not been as fortunate.

Last year, a police spokesman said that during the Persian year ending in March 2014, the Gasht-e Ershad forced more than 200,000 women to sign pledges after they were stopped for not wearing the proper hijab. More than 18,000 cases went before a tribunal. There have also been accusations of abuse, the makers of Gershad note on their website, pointing to videos on social media of women being "beaten and dragged on the ground."

Gershad's creators say they've been overwhelmed by the positive response to their app, and they're currently working on a mobile-friendly web version that could be used on iOS and Windows Phone. They've also received requests for an Arabic-language version of Gershad — to avoid the morality police in Saudi Arabia, most notably — and they're considering bringing it to other markets across the Middle East.

Keeping it up and running in Iran will likely be a game of cat-and-mouse, as well. The app's website was blocked within 24 hours of launching in Iran, and its creators say they're prepared for a broader crackdown. They developed Gershad using Psiphon, a tool used to circumvent censorship in Iran, which they hope will allow users to continue reporting even if the government blocks access to the app.

The developers also acknowledge the potential for abuse; if the Gasht-e Ershad uses the app to spread false information on checkpoint locations, that could seriously undermine user trust. The team says it aims to thwart that through "report limitations" that are already in place, as well as other mechanisms that they're currently developing. Newer versions, for instance, will highlight Gasht-e Ershad locations that are reported by at least three people, and will show the number of reports at each checkpoint.

Erami says it's unclear whether Gershad will drastically alter the dynamic between young Iranians and the morality police, pointing to the potential for abuse or misinformation. But she says it could at least help ease the psychological burden that comes with constantly having to scan street corners for potential trouble.

"It seems to me that the people who created this app are trying to give people the sense that they're more in control of their fate, and that the Gasht don't have as much power as they think they do," Erami says. But, she adds, "I don't know how much of a false sense of safety that is."

This article has been updated to clarify Gershad's reporting system.