The half semester is a patent-based app for problem-solving and repetitive learning, including essential English vocabulary and grammar problems for elementary, middle and high school TOEIC, English conversation, Korean vocabulary, social studies/science, 1000-character Chinese characters, Korean history/Chinese character proficiency test, certified real estate agent, current affairs knowledge, medical terminology, etc. You can automatically repeat learning key questions in various categories, set the number of questions per day, auto-execute, set the number of intermediate repetitions, save memorization completion, random OX by day in test taking, unlimited multiple choice questions, solve incorrect answers, save scores, etc. It is designed to achieve maximum learning effectiveness with minimum effort by providing the following functions.