Page Builder
This theme is integrated well with Live Composer plugin to create content with Drag and Drop interface.
You can Check plugin's main website for more information http://livecomposerplugin.com/
You can also try their guided demo to get understanding of the plugin. http://livecomposerplugin.com/playground/tutorial-chapter-one/?dslc=active
This plugin does have learning curve of around 1-2 hours. But once you get used to of it, its addictive. :)