WiseApp, an app analytics company, said 4.28 million people used the AR mobile game on Thursday, up from 2.91 million people on Tuesday when Pokemon Go was officially released in the Google Play Store and Apple's App Store in South Korea.
WiseApp also said the number of people who have downloaded the game fell to 850,000 on Thursday, down from 2.83 million people on Tuesday, citing its sample survey of 17,400 smartphone users.
The app analytics company said the survey had a margin of error of plus or minus 0.74 percentage point.
"Pokemon Go" didn't work in most parts of South Korea as the AR game uses data from Google's mapping service, which is restricted by the Seoul government due to security concerns.
However, tens of thousands of local users have downloaded the mobile game since its launch in the United States in July 2016.
Game developer Niantic Inc. opened its service in South Korea earlier this week after collecting all map data available to the public.
In "Pokemon Go," players are encouraged to cover large physical distances searching for characters and objects rendered from computer graphics that look like they exist in the real world when viewed on a player's phone.
Available in more than 130 countries around the world, "Pokemon Go" has been downloaded 500 million times. And players of this animation-based AR game have collectively walked over 4.6 billion kilometers while playing. (Yonhap)