The TOEFL Junior test has gained popularity in Korea as a means to help evaluate students' English proficiency. ETS explains the test as "a low-stakes assessment that measures the degree to which middle school students have attained proficiency in the academic and social English-language skills representative of English-medium instructional environments."

To help students prepare for the test, e-future has released the TOEFL Junior preparation series.
The e-future TOEFL Junior preparation series has one book corresponding to each area of the test:

TOEFL Junior: Listening Comprehension
TOEFL Junior: Reading Comprehension
TOEFL Junior: Language Form and Meaning

While the series is localized to the Korean market and includes test taking tips in Korean, e-future is considering an English-only version for the international market. Also, those interested in licensing the content are encouraged to get in touch: inquiry@eltkorea.com