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.

RemNote - All-in-One Tool For Thinking & Learning

POLAR - A powerful document manager for Mac, Windows, and Linux for managing web content, books, and notes and supports tagging, annotation, highlighting and keeps track of your reading progress.

Memrise - Learn a new language with games, humorous chatbots and over 30,000 native speaker videos.

Zotero - Zotero is a free, easy-to-use tool to help you collect, organize, cite, and share research.

Quizlet - Quizlet allows you to review and create flashcards for a variety of subjects, such as math and reading.