I would like to introduce you to a new WordPress plugin that I wrote (or rewrote), it is called WP-DraftsForFriends. The last time I wrote a plugin was almost 3 years ago which was the WP-ShowHide!
The plugin is on GitHub as well, github.com/lesterchan/wp-draftsforfriends.
This plugin will generate a unique link that you can send to your friends to allow them to preview your draft before they are published. You are able to set the expiry for the link as well. It is based off Drafts for Friends originally written by Neville Longbottom.