Lumin is a free revision app combining Duolingo's gamification with Quizlet's study effectiveness. Unlike other revision tools, Lumin teaches before it quizzes — with worked examples, reading cards and hints. Built for GCSE students with AQA-aligned content across Maths, Biology, Chemistry, Physics and Computer Science. Features include spaced repetition, XP, streaks, a mastery map, focus mode and an interactive piano for Music Theory.