This plugin is a excellent companion of Advanced Custom Fields PRO and Quick and Easy Post edition for ACF Relationship Fields PRO. When dealing with Relationship or Post Object fields (which links a post to one or multiple other posts), you often stumble on having to link to a post that does not exist yet. This is a frustrating and time-consuming experience: you have to save the content you were working on, then create the new post, and finally reload your primary content to be able to link to the newly created post.