Frontier Set Featured will set featured image from images in the post if no featured image is set by the user.

Main Features

• If no Featured Images is set on save, the plugin will:
  • Select the first image that is uploaded to the post, and set it as Featured Image
  • If still no Featured Image, select the first image from the post content, and set it as Featured Image
• The will work both from admin interface & frontend.

Note: Only images from the media library can be used as featured images (as per WordPress standard).

Frontier Set Featured wordpress.org: Download Plugin | Plugin Support