The idea for this plugins, is Widget Logic WordPress Plugin, on My Snippet WordPress Plugin (develop by Justin Tadlock) give extra content on your post. Example we can add Featured Video on current content and many more.
How the plugin works
First, you’d add the Snippet widget to the widget area of your choosing. You’ll need that to display your custom snippets.
When writing a post (or page), you’ll have an extra meta box labeled Snippet Post Settings. In this box, you can add text, HTML, and shortcodes.
Download the plugin
Before using the plugin, please take a moment to read through the
readme.html file included with the plugin download. You can download this plugin from WordPress.org