刘老师系列-3上互动练习 is an educational application designed for iPhone devices. Developed by 成城 高, this app allows users to learn elementary English anytime and anywhere. It features synchronized audio readings of the latest elementary English textbooks, with a unique voice correction function to improve pronunciation. Parents can also use the recording check feature to ensure the quality of their child's English reading. The app provides high-definition and realistic book pages, with professional teachers offering lecture explanations and answers to classroom questions.

The app offers various functionalities, including synchronized explanations of the text by professional English teachers, audio readings synchronized with the textbook, and full-text translations. It also includes a pronunciation correction function, allowing students to compare their own pronunciation by repeatedly reading aloud. The app also allows for recording and checking of readings by parents, as well as vocabulary dictation exercises with correct pronunciation provided by the app.

Additionally, the app offers practice exercises for key sentence patterns and word combinations. Recent updates in October 4, 2018, have improved the word dictation and statistics features, added a text-guided recitation function, and made the app compatible with all iPhone and iPad devices.