This document summarizes the features of the Zhi Mi Bei Dan Ci (Know Your Words) app for learning English vocabulary. The app includes: 1) A study plan for learning new words and reviewing words. 2) A scientific learning model of identification, presentation, and extension of new words. 3) A scientific review model that incorporates the forgetting curve and recycles words through listening and spelling exercises. 4) Vocabulary books and reading materials to provide context for learned words. 5) Online community features for social learning and peer supervision.