efTeacher is a mobile application designed to help users learn and improve their French language skills. It offers a collection of exercises and tests that cover different levels of difficulty, from beginner to advanced. With efTeacher, users can learn new words, practice correct usage of words in various contexts, grammar, and use of French in various situations.

The app provides two modes of learning: LEARN and TEST. In LEARN mode, the app repeats the question when the user gives a wrong answer, and the exercise only ends when the user finally gives correct answers to all the questions. In TEST mode, each question is asked only once, and the user gets a score based on the percentage of correct answers.

The app is best suited for kids learning French at school. It offers over 200 exercises, with 20 exercises available for free, while the rest must be purchased. The difficulty levels are represented by the color of the icons, making it easy for users to choose the appropriate level for their skill level.