As already mentioned by other none of my projects would work without a database. I can setup a local CI in less then 15min. Then i have model, DB, css, and everything else. I can use a IDE and trace and step through the code inspect variables and objects. All of this is hardly possible in a fiddle environment. At first glance the idea seems "nice to have" but if you think about it more its far easier to setup a fully fledges local test site.
On the package it said needs Windows 7 or better. So I installed Linux.