This app changed my way to build websites - especially web templates. I have heard about SASS, LESS and CoffeeScript before but this app was the reason why I had a closer look at those tools. Now I don't know why I ignored those great tools!
I have some minor issues with the app (e.g. changing the output of SASS files won't apply when working on an existing project) but I am sure those small problems are either because I still don't fully understand the app or they will be fixed in a future update.
There also is one feature I would like to be added: automatically add the files from the Frameworks to the project folder. I have some scripts working with other files (PHP, images, ...) but I only can include javascript files in my project when adding a framework.
If you are new to web development, this app may be not for you, as you will have to know the tools (CSS, HTML, Javascript, SASS, ...) or you should be willing to learn a lot. But if you know to code, this app is very helpful and adds a nice GUI to the included tools.