Anki is an open source flashcard program for spaced repetition that hands the timing of reviews to the FSRS scheduler built into it, and includes a free service for syncing between devices. It suits learners who need to hold a large mass of small facts over the long run.

An open source reader for six platforms that opens more than fifteen ebook and comic formats, keeps everything local by default, and adds cloud sync, four annotation styles, translation and read-aloud for people who want to read rather than manage a library.