Khan Academy
You’ve probably heard of Khan Academy before — and for a good reason. This app has everything you need to learn about many different topics, from math and economics to grammar, and politics.
And the best part about this is that it is completely free. Khan Academy is a nonprofit organization, and its mission is to provide free education across the world.
The app comes with many different topics to choose from, and they’ll be tailored to your current learning level. So it doesn’t matter if you’re a teenager or you’re starting university pretty soon; Khan Academy has something for everyone.
You can easily track your progress in the app and study whenever you want. You can even download classes so you don’t use too much data while you’re on the go.