Apparently, an augmented reality game much like 'Pokémon Go' existed in Korea five years ago.
Back in 2011, KT Corporation, South Korea's largest communications/telephone company, had introduced an augmented reality game for mobile devices similar to 'Pokémon Go' called 'Olleh Catch Catch.'
The game involved the running of an app that would use GPS and a map overlay to reveal the locations of 'monsters' on the streets, much like the explosively popular 'Pokémon Go.'
Unfortunately, 'Olleh Catch Catch' didn't catch on and phased out in a year following its launch. It appears it failed to gain traction with the mainstream masses as the game lacked the familiarity and popularity of franchises like Pokémon.