I remember I was in college when it came out, and there was a period of time where if you saw someone on their phone outside, it was probably to play Pokemon Go.
The company behind Pokemon Go has announced it is using data collected by its millions of players to build an AI model that can navigate the real world, and could be used for robots. Doubt Pokemon Go players anticipated this
https://www.404media.co/pokemon-go-players-have-unwittingly-trained-ai-to-navigate-the-world/
Discussion
Yeah, it was a big thing when it came out. Even here in Puerto Rico, I remember there was a day people overcrowded the center of San Juan because of the game, trying to catch a Charizard. Wild how big it got at that time. I am sure they retained a good amount of users since then.