Khan Academy allows you to learn almost anything for free.
Our Windows 8 app is the best way to view Khan Academy's complete library of over 3,400 videos.
We cover a massive number of topics, including K-12 math, science topics such as biology, chemistry, and physics, and even the humanities with playlists on finance and history.
Spend an afternoon brushing up on statistics. Discover how the Krebs cycle works. Learn about the fundamentals of computer science. Prepare for that upcoming SAT. Or, if you're feeling particularly adventurous, learn how fire stick farming changed the landscape of Australia.
It doesn't matter if you are a student, teacher, home-schooler, principal, adult returning to the classroom after 20 years, or a friendly alien just trying to get a leg up in earthly biology; Khan Academy's materials and resources are available to you completely free of charge.
Head over to khanacademy.org to learn more.