Kristopher Lagraff

This plugin enables the short link menu item to display in the admin toolbar. This feature was removed from 
version 3.3 by default.

Reenable Shortlink Item In Admin Toolbar

This plugin will display the shortlink menu item in the admin toolbar.

Philip John

This plugins adds a visible link to the end of every post.
Best used in conjunction with the <a href="https://wordpress.org/extend/plugins/googl-shortlinks/" rel="ugc">Goo.gl Shortlinks</a> or <a href="https://wordpress.org/extend/plugins/bitly-shortlinks/" rel="ugc">Bit.ly Shortlinks</a> plugins.
Feature requests welcomed with open arms!

Add Shortlink to Posts

Adds a link to the shortlink for each post below the content.

Reenable Shortlink Item In Admin Toolbar vs Add Shortlink to Posts