A couple of things: I don't think the dot-org TLD is appropriate for a commercial venture. Your app store link takes me to an itunes web page on the Japanese app store, rather than launching App Store itself.
They should have pointed it to global link
I had a quick look through your CSS (which I think is built using Xpressive) overall I think it looks pretty good. Although you could definitely shave of 30% off by inlining some of the rules. For instance for margin:0 auto; you call margin-left:auto, margin-right:auto.
The same applies for background, using the shorter version cuts files sizes dramatically
Also on Twitter: https://twitter.com/Xpressive_Team
Being able to save code changes in element inspector is nice, any way to do that in chrome?
What were the other killer features?
If I have to go the route of installing a bunch of individual tools and maintaining them separately, then it becomes less appealing.