I don't have time to research this company's technology/system, so I'm just going to throw it out there for the Skritter guys to look at:
http://www.wordengine.jp/

I'm guessing the Skritter staff has seen or heard of it before, since it sounds like it is similar to skritter but for japanese people learning english.

I just came across it because it won the growth stage award at this year's global mobile internet conference.
http://gmic.greatwallclub.com/startup-competition

so my question is, What's so great about it? Why did it win the award and what can skritter learn from it.

I haven't tried it, but it looks like they're using SRS, explicitly skipping words the user already knows, and focusing on tests of English ability. A good approach, I'd say. Skritter implicitly rather than explicitly avoids wasting time on words you already know, since if you never get them wrong, the scheduling pushes them back very quickly.

A further comparison would need more time, and, you know, actually using the product.