Khan Academy

Yo, wanna learn something new? Khan Academy's got your back. Seriously, it's free and you can learn basically anything. Math, science, history, you name it. They have videos, exercises, and articles, all super helpful. Need to brush up on some stats before your next exam? Khan Academy's got you. Want to know how the Krebs cycle works? Boom, Khan Academy. You can practice at your own pace, and even download stuff to watch offline. Plus, it tracks your progress so you know where you're at. Oh, and it's not just for students, teachers, or aliens (though, aliens are welcome!). Anyone can use it. Just keep in mind, not everything from the website is in the app. For stuff like discussions and programming, you gotta go to the website itself.