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Simply activate this plugin to attach featured images to their respective posts in the site feed: https://example.com/feed/. One example of why this is useful is for providing an image for social media sharing through services like Dlvr.it, Hootsuite, HubSpot, etc.

RSS Image

Simply activate this plugin to attach featured images to their respective posts in the site feed.

glashkoff

This plugin add box to posts editor to easy generate an Open Graph images from the post featured images and captions. In popular social networks that support Open Graph or Twitter Cards (Facebook, Google+, Twitter, VK.com (Vkontakte), OK.ru (Odnoklassniki)), links to pages on your site will look noticeable. This should improve traffic. 
Colors and styles are customizable. If post has no featured image, plugin uses solid color.

Open Graph Images With Caption

Generate an Open Graph image with custom caption.

RSS Image vs Open Graph Images With Caption