With my own kinder we are doing Dreambox, which covers most of the K-3 curriculum in a very fun, game-like way and with lots of virtual manipulatives. My kids love it. The biggest drawback: no instruction provided in-game. So you have to do it on the side, or plug in the right (again!) Khan lectures.
I *do* like the Khan Academy lectures for basic subjects because they are well thought, provide context for the material taught, and slow down for the harder stuff (I have always been very bad at explaining things that come easy to me, which would cover most math up to moderately advanced college level).
