Anki - Anki is a program which makes remembering things easy. Because it's a lot more efficient than traditional study methods, you can either greatly decrease your time spent studying, or greatly increase the amount you learn.
vym - VYM (View Your Mind) is a tool to generate and manipulate maps which show your thoughts.
Duolingo - Duolingo is a free language learning app for iOS, Windows and Android devices. The app makes learning a new language fun by breaking learning into small lessons where you can earn points and move up through the levels. Read more about Duolingo.
Freeplane - Freeplane is a powerful and free software for building mind maps.
Kartka - Kartka is a flash card learning tool with real-time sync, spaced repetition algorithm, and a modern and friendly interface.
SuperNotecard - Introducing SuperNotecard. SuperNotecard is an online writing tool that features virtual notecards to help arrange facts or scenes, track details, organize paragraphs, and clarify your composition process.