Its simple interface is really helpful for students of all ages. I personally use khan academy in my mentor sessions at the University of Texas at Arlington to help students understand concepts easily and in an interactive manner. As it is online and free students are able to practice it at their homes and do the quizzes at their own pace.

I like the ability to walk through a lesson, the way it's broken into parts and have practice built in. I also like the fact that the lessons can be done through Khan Academy's site or through YouTube.

I like that Khan Academy has a wide array of topics and is easily able to teach others about topics. It is an easy format often with short videos to help describe topics. It also has helpful quizzes.