Chicago is teeming with tiny, wild creatures.

On every street, it seems, people are pursuing Pokémon characters in a game called Pokémon GO, which has turned the city into a playground.

Using smartphone technology, the free app lets players “catch” Pokémon characters that appear in real-world locations.

By connecting with smartphone cameras and GPS, the app shows virtual Pokémon characters popping up in real places. Players, called “trainers,” have to get up and move to find them.

Pokémon can turn up anywhere, from the train to the sidewalk. When one materializes, users catch it by swiping the smartphone touchscreen to toss a Poké Ball at it.

Pokemon Go is displayed on a cellphone. | Richard Vogel/AP

Pokemon Go is displayed on a cellphone. | Richard Vogel/AP

The goal is the same as it has always been: To catch ’em all.

While the creatures appear in random places, players also can make Pokémon come to them by purchasing “lures.”

The Poké Balls used to catch creatures are collected at locations called PokéStops. PokéStops programmed into the app include sculptures, monuments, CTA stations and restaurants.

One of the stops is D.S. Tequila Company in Boystown.

Franky Mauras, a bartender there, said the app has attracted customers.

“We get a little more traffic,” he said. “In the game, there’s different stops where people can collect stuff. One of them is our storefront — it has the picture of D.S. Tequila on it.”

One popular game destination is near Cloud Gate, and it’s a “gym” instead of a PokéStop. At this and other gyms, higher-level players work in teams to battle others for control of the spot.

An "augmented reality" feature in the Pokémon GO game allows creatures to appear in real-world settings. | Pokémon GO

An “augmented reality” feature in the Pokémon GO game allows creatures to appear in real-world settings. | Pokémon GO

On Sunday, The Bean will be more than a battleground — it’s the chosen spot for the “first ever” Pokémon GO meetup in Chicago, according to the event organizer Sam Guerrero. More than six thousand people said on Facebook they plan to attend.

“It’s bringing communities together,” said Christine Turner, 27, who played Pokemon GO in Millennium Park with her husband, David. “There’s no age gap or age limit to it.”

Christine and David Turner agreed the game encourages physical activity.

“I haven’t exercised this much in two years,” said David, 33.

Users must travel certain distances to incubate Pokémon eggs, they said, and you can’t cheat by driving: Above a certain speed, the app won’t count movement.

“I love that it’s getting people out and doing things,” Christine said. “I grew up watching it, so it’s cool revisiting your childhood in such a way that it’s making everybody get out and walk and do things.”

Player Addy Dharma, 20, who played his first battle at The Bean, said he and his brother have been watching out for Pokémon while visiting Chicago from the San Francisco Bay Area.

Addy Dharma, 20 (left), and his brother Andika, 16, captured Pokémon characters while traveling to tourist sites with their parents. | Angie Stewart/Sun-Times

Addy Dharma, 20 (left), and his brother Andika, 16, captured Pokémon characters while traveling to tourist sites with their parents. | Angie Stewart/Sun-Times

“We’ve been distracted a little bit,” he said. “We’ll be walking with our parents, we’ll open it [and] look to see if we can find any Pokemon nearby.”

When the app launches, a note advises players to “be alert at all times” and “stay aware” of their surroundings.

Twitter user Pokémon Go Chicago posted that there have been robberies by The Bean and Michigan Avenue, but the Chicago Police Department said there haven’t been reports of any incidents in the area connected with the game.

For Nick Meesey, 12, who has been out playing in his neighborhood as late as 1 a.m., it’s a concern that some are gaming dangerously.

“I’ve seen people just stop in the middle of roads, trying to catch the Pokémon,” said Meesey, who’s from downstate Champaign. “You just gotta look where you’re going.”

A player on the yellow team, 12-year-old Nick Meesey said his best advice for other Pokemon GO players is to "buy a portable charger because it sucks your battery out." | Angie Stewart/ Chicago Sun-Times

A player on the game’s yellow team, 12-year-old Nick Meesey, said his best advice for other Pokémon GO players is to “buy a portable charger because it sucks your battery out.” | Angie Stewart/Chicago Sun-Times

The game is the latest resurgence of Pokémon, which started out on the Nintendo Game Boy system.

It was created by software company Niantic Inc., an internal startup at Google. Niantic founder John Hanke also was behind Keyhole, which was acquired by Google Earth.

Catching Pokémon on smartphones has caught on quickly. Niantic released the app just last week for iOS and Android devices in the United States.

It’s already the top grossing app in iPhone’s App Store. Within days of its July 6 release, Pokemon GO was downloaded on more Android phones than Tinder and had more user engagement than Twitter,  information technology company SimilarWeb found.