Buffl is a free, cross‑platform learning app that lets users create and study flashcards and multiple‑choice questions on any subject, from school topics to employee training. Users can build courses, import vocabulary lists, add images, and organize cards into stacks, with automatic cloud sync and offline access. The app employs a five‑box Leitner system for spaced repetition, offering fast, random, and speed learning modes along with progress tracking. Content can be shared publicly or privately, and the interface supports light and dark themes.