Divshot
Divshot is an interface builder for web apps that exports clean, semantic code. You can edit the code by hand and changes will be reflected instantly in the WYSIWYG editor. Divshot supports Bootstrap, Foundation and Ratchet. A theme chooser lets you preview the design using Bootswatch and other themes. Built-in JavaScript functionality from Bootstrap is available, but there are no features to add JavaScript code to the page.
Excellent tutorial guides the user through Divshot's features. Limitations: can't comment on the page (see Easel for that), limited set of attributes editable by the inspector (essentially, framework styles, but no lower level attributes like padding or roundness - see Easel for that)
