Materialis is a free theme for WordPress created by Extend Themes.
Materialis is an incredibly flexible, multipurpose WordPress theme that can help you create an amazing website easier than ever, by drag and drop. It uses beautiful material design and it comes with a predesigned home page. It also has lots of customization options (video background, slideshow background, header content types, gradient overlays, etc) that will help you create a beautiful, unique website in no time. Materialis is responsive so it works on mobile devices out of the box.
(Description "Materialis" Theme from wordpress.org)
You can download Materialis for free via the provided download link and include it into your themes folder of your WordPress installation. Also you can directly search for it in the WordPress admin interface in the themes section and install and activate it from there.
More information, screenshots and reviews of Materialis Theme can be found here.