Twitter Bootstrap is becoming more and more popular, many use it in their projects, I think even more people use it to prototype interfaces. I'm not an exception. And this morning I came across an interesting service -
LayoutIt . In essence, LayoutIt is an online editor for creating interfaces using Bootstrap. The editor is a Drag & Drop interface.

Let's take a closer look at it. Just want to say that the project is still in beta and not all components and features of Bootstrap can be used. So, for example, on the JavaScript tab, it flaunts Cooming soon ... It’s also impossible to put icons in buttons.
The editor interface looks like this

On the right, we see tabs with Bootstrap components. Grid System - select one column, two or three. Base CSS - the main elements such as buttons, lists, tables, forms, and more. Components - various additional components.
After that, all you have to do is drag and drop items and select their properties. It looks like this

After you are done, you can view a preview using the top menu or download your code in zip or html format.
The editor is still far from ideal, there are not enough many components, there is still something to work on. But for a quick sketch, it fits almost perfectly.
Website:
LayoutIt