Tyler Johnson

This plugin searches your posts for YouTube embeds and then wraps the player with share buttons that appear on hover when view on desktop or display on place when view on mobile devices. There’s both a share button for Facebook and for Twitter that share your current post URL. When the post share on Facebook, it share the full URL. When sharing on Twitter however, it uses the shortlink, so that the tweet does not surpass the 180 character limit. It works with both regular YouTube iFrame embeds and the oEmbed system.
View the demo here: http://wpdevelopers.com/wpdeveloper-youtube-share-buttons/

WPDevelopers YouTube Share Buttons

Plugin that automatically creates share buttons over YouTube embeds that appear on hover when viewed on desktop or display on play on mobile devices.

WEB4PRO_co

This plugin creates widget and shortcode with YouTube subscribing channel form or button.

YouTube Subscriber

This plugin creates widget and shortcode with YouTube subscribing channel form or button.

WPDevelopers YouTube Share Buttons vs YouTube Subscriber