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.

Kostas Vrouvas

Get the classic “Get shortlink” from WordPress 3.7. Developed to make it easier for people at <a href="https://mentorinculture.com/" rel="nofollow ugc">Mentor</a> to get shorlinks and open sourcing it.
To-do:
<ol>
<li>Connect with Bit.ly API</li>
<li>Options menu to add Bit.ly API keys</li>
</ol>

Get Shortlinks

Get the classic "Get shortlink" from WordPress 3.7. Developed to make it easier for people at Mentor to get shorlinks and open sourcing it.

Reenable Shortlink Item In Admin Toolbar vs Get Shortlinks