Walking down Dulany Street in Alexandria, Virginia, the plaza where I usually see people sitting and having lunch has transformed into a Pokémon Gym, where people battle their Pokémon against other users. I was told the ownership of the gym changed a few times before lunch Monday.

As I walked around trying to catch Pidgey, an avian-type Pokémon, I found I wasn't the only one holding up a cellphone and walking around itching to spot a wild Pokémon for capture.

Millions of people all across the country are reliving the nostalgia of Pokémon, while others are being introduced to it for the first time via the new smartphone game Pokémon Go. The app is a level up from the video game of the late '90s, cards and the anime series — this version is getting people up and moving.

Since its U.S. release date July 6, around 7.5 million people in the U.S. have downloaded the Pokémon Go app from Google Play and the iOS App Store. The app has surpassed the number of downloads of the dating app Tinder and has nearly the same amount of daily users as Twitter.

From its success, Nintendo's stock has risen 25 percent and growing.

"Pokémon Go is a one-and-only game because it is a marriage of famous characters that everyone knows and the cutting-edge technology powered by Google," said industry analyst Hirokazu Hamamura, a director at Kadokawa Dwango Corp.

During my lunch walk, I checked out King Street Metro Station (top). I also captured a wild Rattata that appeared at the corner where our office is located (left). The lion statue that sits at the corner of Dulany and Duke Streets is another checkpoint for users to catch poke balls and other items (middle). And the gym is where people battle their Pokémon against other users (right).

While Nintendo is currently reaping the rewards of this profitable app, users are also getting an unexpected benefit — exercise.

When I spent my lunch break looking for and catching Pokémon, I had to walk my way around the area to find them, unlike a majority of gaming apps that require little to no movement. The Pokémon Go app uses augmented reality and GPS tracking that allows players to capture Pokémon, collect Poké balls and interact with other gamers.

By the time my hour-long lunch break was over, I was a little over 4,500 steps of my 10,000-step goal for that day.

If the app continues to motivate users to get up and go, it may even help to shrink the numbers in obesity, an issue that is a growing concern in the U.S. According to data from the National Health Interview Survey 2015 by the Centers of Disease Control and Prevention, 30.4 percent of U.S. adults aged 20 and over were obese.

However, as users walk around catching Pokémon, it is also leading to injuries.

"I just wanted to be able to stop quickly if there were any Pokémons nearby to catch," said 21-year-old Mike Schultz from Long Island, New York. Schultz fell from his skateboard, cutting his hand on the sidewalk while staring at his phone trying to capture Pokémon.

Police are also warning users to stay off private property.

"Deputies have located numerous individuals on business, church and government properties at all hours of the night, when these places are closed to the public," the Goochland County Sheriff's Office in Virginia posted on their Facebook page.

In Australia, the Northern Territory Police, Fire and Emergency Services are giving players a different warning: Don't hunt inside the station.

"For those budding Pokémon Trainers out there using Pokémon Go — whilst the Darwin Police Station may feature as a Pokéstop, please be advised that you don't actually have to step inside in order to gain the poke balls. It's also a good idea to look up, away from your phone and both ways before crossing the street. That Sandshrew isn't going anywhere fast."

"Stay safe and catch 'em all," the Australian police force wrote on its Facebook page.

I took their advice after work while trying to catch Pokémon and Poké balls. This time around I did about an hour and half worth of searching. I now have a grand total of 14 Pokémon and a pair of sore legs — and I reached my goal of 10,000 steps for the day.

During my walk after work, I ended at Fed Ex Field, home of the Washington Redskins. In the Pokémon Go app, the football field is the stadium itself. The solar man picture to the right is the solar installation that is at the entrance to the stadium. On the Pokémon Go app it is a checkpoint, where players can get Poké balls and other items.