CASEC V:A Vocab Master in your pocket CASEC V is a mobile appl that is focused on building vocabulary of an individual. It is an English Vocabulary - Study and Assessment app.It provides 1717 vocabulary words which are divided in 4 different levels [Platinum, Gold, Silver, Bronze]. User should start with"Know Your Level"option. The quiz, based on IRT (Item Response Theory), provides 10 unique multiple choice questions. Once you start quiz, you cannot navigate to previous question.