CHICAGO — As another storm flung snow at Chicago, Alexandra Clark wondered how she’d get to work. Like an increasing number of snowbound city dwellers, she had a ready tool at hand: an app that tracks hundreds of city snowplows in close to real time.

But something seemed out of whack.

“Plow tracker said my street was plowed an hour ago — Pull the other leg,” the 31-year-old video producer tweeted at the mayor’s office, including a photo of her snowed-in street.

Across the country, local leaders have made plow-tracking data public in free mobile apps, turning citizens into snow watchdogs and giving them a place to look for answers instead of clogging phone lines at city call centers to fume. Chicago and New York introduced apps in early 2012, and Seattle has gotten into the game, as have some places in Maryland and Virginia.

Boston briefly experimented, too, though their site was so popular it crashed during a February 2013 storm, hampering the effort. The city hasn’t made another attempt.

The apps tap into GPS data already collected by the city to direct plows, so no extra money is spent in the creation.

But in New York and Chicago, in particular, the tech savvy have scrutinized the sites. Armed with the ultimate proof — the cities’ own data — they’ve needled public officials about snow-cleanup shortfalls on social media.

“It puts a lot of pressure on everybody involved to be more responsible and to be more accountable,” said Priscilla Dixon, a Chicago lawyer who used the app.

Clark remembers peering out the window of her Wicker Park apartment on the city’s West Side in a January 2014 storm. A pair of heavy truck tire tracks suggested a GPS-equipped plow might indeed have passed, but with the blade up.

“No joke, the next week when it snowed overnight, a plow had come through and taken off the side mirror of my car,” the California-native recalled with a laugh. “It’s probably coincidence but after that I really didn’t tweet much to the city of Chicago anymore.”