The timeline editing is pretty cool. But you could easily get automatic vendor prefixing with SCSS/SASS (and you should be using a compile-to-CSS language if you're doing serious web design), and automatic reloads with Vogue or LiveReload. If I wanted to do serious CSS animations, though, this is worth a shot - and it's a great tool for inexperienced web designers or those short on time.

I was asking because the OP to my comment implied it could be done with just a browser and CodeKit. I'd rather keep the number of dependencies to a minimum. I haven't used Chrome for front-end dev work for some time, so maybe it's added these features. And CodeKit does compilation, so I figured it would have this.

If I have to go the route of installing a bunch of individual tools and maintaining them separately, then it becomes less appealing.

Yeah, I get that. It depends on how often you do web work. If you do it as often as I do, it makes a lot of sense to put in the extra effort now to streamline you work in the future. But obviously that doesn't apply to everyone.