Koh Younghoon, a board member of the Korean Association for Public Interpretation and Translation (professor at the College of Occidental Languages, Hankuk University of Foreign Studies), published FLEX UP Indonesian in November 2021. The first print of FLEX Indonesian Koh was published in 2015, followed by a second print of the first edition in 2016, and a third print of the first edition in 2019. Although there are relatively few readers compared to English textbooks, the record of publishing three prints over four years seems to reflect the increasing demand for Indonesian language education in the recent era of the New Southern policy.​