RSS feed icon is a WordPress plugin by Arthur Gareginyan that lets you easily add the RSS feed icon by using a simple shortcode in any place of your website, such as: header, post content , page content, sidebar and/or footer.
Features:
Responsive
Retina support
Cross Browser Compatible (work smooth in any modern browser)
Simple shortcode for displaying the RSS feed icon
8 integrated icons from IconFinder.com
Ability to upload your own icon
Ability to set the size of icon
Ready for translation (POT file included)
More info and download: https://wordpress.org/plugins/rss-feed-icon/