External Url As Post Featured Image (thumbnail) Wordpress Plugin - Rating, Reviews, Demo & Download
Plugin Description
Set External-URL as post thumbnail url. (For developers: you can also use a filter-hook to programatically set external url as post’s thumbnail):
add_filter("external_thumbnail_url_for_post", "your_function", 20, 2);
function your_function($existing_external_url, $post_id ){ }
To get thumbnail url with function:
$GLOBALS['ExternalUrlAsThumbnail_PP']->get_post_external_thumbnail_url( $post_id );