Caos is a free theme for WordPress created by Quema Labs.
Caos is an incredible blogging theme using the new WordPress REST API for an AJAX experience. With an unique responsive design making it unlike any other theme.
(Description "Caos" Theme from wordpress.org)
You can download Caos 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 Caos Theme can be found here.