Johnson's Pokédex shows that he's caught all 142 Pokémon available in the United States. Nick Johnson Brooklyn-based Nick Johnson, who happens to be a friend of mine, has publicly declared himself to be the first Pokémon Go player to catch all of the 142 Pokémon that we know are available in the US.

According to the original video games that Pokémon Go is based on, there are 151 total monsters. We know that there are 142 you can catch in the US, plus three more exclusive to certain international regions, but nobody can account for the whereabouts of the other six.

Johnson's journey to Pokémon mastery took a lot of doing and some long nights, he tells Business Insider, but it was worth it to fulfill his childhood dream of catching 'em all.

On Reddit, Johnson's announcement that he completed his collection as much as possible raised eyebrows: Commenters accused him of cheating or otherwise faking his accomplishment.

But, speaking personally, I've gotten enough late-night Facebook messages boasting of a new Pokémon capture to vouch for his dedication and thoroughness.

Johnson, head of platform with startup Applico and a recently published author, doesn't have a lot of time to play during the day. So, right after leaving work around 6 or 6:30, Johnson tells Business Insider, he would start walking around Manhattan and Brooklyn in search of Pokémon.

Those treks could last for eight hours at a time, Johnson says, walking until he had to come home and pass out. His iPhone's Health app tells him that he's walked an average of 8 miles a day in the two weeks since the game came out.

Some other highlights from his Pokémon Go adventure:

He chose water-type Squirtle as his first Pokémon because he didn't realize that he had a choice. He would have gone with the fire-type Charmander, in reflection of his choice of Team Valor, the game's red team.

The very last Pokémon he needed for his collection was Omastar, which he evolved himself. He says that he would have caught it a day earlier when two appeared in his vicinity — but then Verizon cell service cut out for 15 minutes, denying him of his prize. " Shout out to Verizon, you the real MVP," Johnson jokes.

Shout out to Verizon, you the real MVP," Johnson jokes. The second-to-last Pokémon that Johnson needed, Porygon, was also the hardest, and required a trip to Jersey City. "I may or may not have seen it on the radar and then ordered an Uber to drive me around until I found it," Johnson says.

The best spots in New York City for catching Pokémon are Battery Park and Grand Army Plaza in Central Park. The latter is where Justin Bieber was spotted playing, and on any given night, there are 300 or so people gathered there for Pokémon hunting purposes, staying "well until the morning."

His best tip for would-be Pokémon masters: "Buy some good walking shoes." He also recommends that if you're going to spend real money for in-game items, then the egg incubators are the best bang for your buck.

Johnson shares his tips and strategies for completing your Pokémon Go collection here.

Even with his Pokémon collection complete, Johnson says that he'll keep on playing, though he hopes that Pokémon Go developer Niantic improves Gyms and the game's battle systems to "make them more fun." Plus, his girlfriend still has to complete her collection, so he has to help her out.

Applico's head of platform, Nick Johnson. David Won Ko

"But I will probably sleep more," Johnson says.

And on a final note, Johnson notes that there are three Pokémon — Mr. Mime, Kangaskhan, and Farfetch'd — who are available only in Europe, Australia and New Zealand, and Asia respectively. He says that he's actually writing to travel sites and startups looking for someone to sponsor his world tour to complete his Pokémon collection.