Shopware is currently in beginning phase and due to which developers are more interested in making themes to sell and make money instead of helping community to grow any how i managed to find two free themes from official store.
1. Responsive Theme – 8mylez
If you ask me how my experience was for this theme I would say it was really good. Products could be displayed in wide and big pics and inner pages offers most of the required information related to that product you want to sell.
2 . Free Shopware Retina ready Responsive Template
Really nice effort by developer. You have to download and install the plugin and Responsive Kit as your template. It is basically created to make your default theme work on mobile devices and tablets. Error free CSS and 479 icons ready. Nicely optimized for search engines.
See how google see it