Ive tried using this on a 9.7" iPad Pro with iOS10. I really wanted to like it. The scoring system is nice for tracking progress, the videos are reasonably helpful and the aesthetics are pleasant. However, it just doesnt work consistently. Some things load and some dont. Sometimes it will recognize your inputs and sometimes it wont. The lessons with the little page icon next to them just dont load at all. You are met with a blank screen after you click on it. And some of the regular lessons wont load at all. This isnt acceptable. Maybe using the Khan website is better, I dont know and I wont bother finding out. I would rather pay for something that works than use something for free that doesnt. My advice to Khan, finish your apps before releasing them, and make sure all of the features work!
teddybearhammer about Khan Academy, v4.2.1