Without announcement or fanfare Mob Psycho 100: Psychic Battle became available for download on the NA App Store. It appears that the game is still in Beta, as the only server playable is a Test Server, and the Server page is labeled as Beta.
Perhaps the server is the Open Beta that has been ongoing in CA and AU, and it became available on the NA App store because of the approach of official launch? Whether this was done deliberately or is a mistake is unclear, as there has been no official announcement as yet. However, in the game announcements, there is a note that says:
In order to prepare for the official launch of the game. We will have maintenance on January 8th, 2020, from 02:00 - 18:00.
Whether this is the launch date or not is unclear. Follow the social media accounts (links below) for up-to-date info!
Stop the work of evil spirits in full 3D RPG-action! Assemble a team of psychics, buff guys, and middle school delinquents as you take on the bizarre spirits threatening everyday life in Seasoning City!
Create a first-in-class dream team of Mob Psycho 100 psychics as you immerse yourself in Mob’s world! Work together to take down spirits & such to the tune of the original voice acting cast in this turn-based RPG!
Mob Psycho 100 started as a Japanese Manga created by ONE on April 18, 2012 and ran until December 22, 2017. An anime adaptation was produced by Bones that ran in 2016, and Mob Psycho 100 II aired from January 7 to April 1, 2019, and was simulcasted by Crunchyroll.