[Source]I am not sure how Korean website ThisIsGame.com got this insider news, but apparently a mobile game based on the TERA IP will be revealed before mid-2014. The game is supposedly still in development, and the Chinese media has talked about a card-based game with TERA characters.

This will be the first time Bluehole Studio develops a mobile game, and it was confirmed some months back that a “sequel” to TERA is being worked on. The game recently introduced its first new class in 3 years, which can be seen here.