You need CodeKit
Mac Users Only
CodeKit is a very early Beta but it is extremely kickass. I'll admit it has crashed twice on me when importing a new project directory but no issues with it's functionality besides that. CodeKit does all kinds of stuff, but the little things are what make me happiest. You can read all about it on the website but i'm going to point out a few of my favorites.
Yes. This is the first application I have found that does an excellent job refreshing my browser when I make changes to my files. The instant I save my html, css or even imported less files-my chrome window refreshes. Codetastic!
He already had Less.app that I used to compile my less files. But. This does that too. Plus Sass. Plus Stylus. Plus CoffeeScript. And it's ka-freaking-awesome.
Something that I am definitely going to love is the frameworks. You can add a local directory with your framework files and easily import them to any project. This means you don't have to include a separate copy of your frameworks in each project folder. Perfect time for you guys to get acquainted with my less framework Lessentails.
Optimizes image files and compresses scripts. I have a couple apps laying around that do this but it's nice to have an all-in-one toolkit.
For now it's free to download (while in Beta) and will be $10 on the mac app store. I'd gladly pay more then that but I'm not complaining.Get it now!