Unsurprisingly, Khan Academy followers can’t get enough of the product: online education tutorials that are easy to use and, best of all, free.
The site has thousands of math and science tutorials, and a decent library of finance and history lectures too. The video lessons are delivered in digestible 10-20 minute chunks, with corresponding online exercises. Students earn badges at each level, including Khan Academy’s version of a Masters. According to the site, they’re great incentive to young Khan Academy users, who collect the badges like Silly Bands.