Webflow - a visual-based responsive web design app | Click image for more info and to try a demo.
Revera is a free premium wordpress theme based on the Bootstrap 3 framework. This is a responsive wordpress theme with all the bootstrap goodness packed in it. The theme is WordPress 3.6 ready. The theme comes with features like, custom menu, featured images, custom homepage template, portfolio page template , widgetized sidebar and footer, custom widgets on homepage, theme option page etc.