Hi,
I've been using Skritter to study for about 3 days now, and I love it. The only flaw I've noticed, however, is that Skritter doesn't really teach the English definition of the words one is learning; I now have a few undefined words floating around in my mind.
The question, then, is how to fix that, and I think one of the best ways would be to have Skritter say the Chinese word and show the characters, then ask for a definition. It could also work in reverse (e.g. Skritter gives the English, and you type in or draw the character).
Cheers,
Gregory