The jQuery Masonry extension makes it possible to create (grid) layouts that adapt to the screen size dynamically (responsive layout). This is a wrapper for David DeSandro’s Masonry jQuery plug-in, but it has been optimized to work with WWB.
http://www.wysiwygwebbuilder.com/masonry.html
You can download the new extension through the Extension Manager (Menu->Tools->Extension Manager->Available).
Please read the help!