This plugin allows you to embed posts into other posts.
Someone needed this capability and did not have it. 10 minutes later you can use a shortcode. ¯\(ツ)/¯
Simply use the [embed_post post_id=19] shortcode with the post_id that you need.
You can also use class=class_name if you'd like to have your own style of embed.
Two styles are currently built-in: default and seamless.
You can also output the excerpt by using excerpt=true.