(NBC News) - Adults and kids have embraced their inner Pokémon fanatics following the July 6 release of the free Pokémon Go smartphone app. The mobile Nintendo game, which now has more daily U.S. users than Twitter, has brought the cartoon pocket monsters to life and has users frantically searching to "catch 'em all."
Confused by all the commotion?
Here's what you need to know about the Pokémon craze that's sweeping the nation:
What is Pokémon Go? Pokémon Go integrates the fun of searching for Pokémon — the imaginary digital creatures that first came to life in '90s-era video games — into real life using your smartphone. The app combines geocaching, an activity that uses GPS technology to place and locate new items and creatures, with the concept of augmented reality, or a live view of the real-world environment with added computer-generated input — in this case, the Pokémon around you.
The app developed by Niantic, a gaming company, uses your phone's GPS locator to place Pokémon in your vicinity. On the app, the creatures come into view alongside real life objects, and many times the kind of Pokémon you can find — water, grass, fire and other types — depend on how close you are to those things in the world.
The aim of the game is to "catch 'em all," while also visiting Pokéstops and Gyms to collect new creatures, items and battle other trainers along the way. However, unlike the original Pokémon video games, the user has to physically move around in order to encounter these creatures.
So what's the big deal? Lots of Pokémon Go players seem drawn to this game because it brings a childhood dream to life: What if Pokémon were real and hiding, say, in my backyard? Or down the street? These pocket-sized monsters, created more than 20 years ago, have now made a resurgence into everyday life with Pokémon Go, and the free app is easy to download and play without any prior Pokémon experience. That's got millions of people pretty excited.
Where are people playing? Basically, everywhere.
But users are sometimes finding Pokémon in unexpected and uncomfortable locations. Users have had encounters with these virtual creatures in hospitals, while driving, in the bathroom and at funeral homes. A 19-year-old in Wyoming in search of Pokemon by her local river discovered a dead body instead.
Players in Cincinnati were on their way home after searching for Pokémon when they came across a slowly-rolling car with two unconscious people inside, and they saved the car from rolling off the overpass. If they hadn't been searching for Pokémon, they would have been home, affiliate WLWT reported.
Pokemon Go's many users are even meeting up for large-scale Pokemon catching sprees. Certain items in the game, such as a Lure Module, can cause more of the creatures to congregate in one area to be caught by many users at one time. These large-scale meetups allow players to catch more Pokemon and meet other enthusiasts in person.
Some players are using Pokémon Go for less admirable purposes. A Missouri police department reported Sunday in a Facebook post that four people used the Nintendo app to target victims in armed robberies in the St. Louis area. Authorities said the suspects used a Lure Module to attract players away from their homes and towards the possibility of catching Pokémon.
Others have gone above and beyond in search of Pokemon, injuring themselves along the way. "Pokemon Go put me in the ER last night," one player wrote on a Reddit page devoted to the game.
"Not even 30 minutes after the release last night, I slipped and fell down a ditch," the user wrote. "Fractured the firth metatarsal bone in my foot, 6-8 weeks for recovery … Watch where you're going, folks!"
Who's playing? Pokémon Go has captured the attention of many high profile users. With over 7.5 million downloads of the game in its first week, it's no surprise that celebrities and organizations want to get in on the fun.