[edit: thank you for all the replies!]
[edit: thank you for all the replies!]
Native apps save bandwidth on each request by relying on the API, which primarily transmits semantic data rather than presentational data. On a slow, metered connection, that's significant.
And, once the exercise framework lands on Android, it oughta have way better performance than the current Javascript implementation that the mobile website uses - especially for manipulating those fancy graphs. When users are frustrated by KA's unresponsiveness, they drop off and don't learn.
That said, the current Android app is definitely just a starting point; until exercises and all the personalized learning features land, mobile web will still be the best tool for KA's non-casual mobile users.
You can easily draw your calculations anywhere on the screen, and when entering final results, you handwrite it, making square roots and fractions so much easier.
It is much more fun to do math problems on the iPad app than any other way I've tried.