José María Ferri Azorín

This plugin is based on <a href="https://wordpress.org/plugins/tiny-url/" rel="ugc">Prasanna SP Tiny URL</a> plugin and uses some of its code.
This plugin shows a short URL for each of your blog posts after post content (in FrontEnd). Short URLs are great for sharing your posts on micro-blogging sites like twitter, identi.ca etc., This plugin sends current post or page URL to <a href="https://v.gd" rel="nofollow ugc">v.gd</a> or <a href="https://tinyurl.com" rel="nofollow ugc">TinyURL.com</a> and gets a short URL for the same. Then it shows that Short URL after post content. You can select which users can see short URL textbox: “All users”, “Regitered users” or “Registered users that can edit the post/page”. User can just click on the box to select URL, or click on a Copy button to Copy the Short URL to clipboard. You can also show Short URLs for pages by selecting Show Short URL FE on pages option in plugin settings page.
Note: Please read V.gd <a href="https://v.gd/terms.php" rel="nofollow ugc">terms of use</a> before activating the plugin. You must abide by them after activating the plugin. 
Note: Please read TinyURL’s <a href="https://tinyurl.com/#terms" rel="nofollow ugc">terms of use</a> before activating the plugin. You must abide by them after activating the plugin. TinyURL is a trademark of TinyURL, LLC
<h4>How to style the output?</h4>
You can add a class for textbox and a class for button on Short URL FE plugin options page.
The output of this plugin is wrapped in a <code></code> tag with class <code>short-url-fe</code>. Use this class and, optionally, your classes to style them. 
Example,
<pre><code>/* this change background color for area where plugin is shown */
.short-url-fe {
 background-color: #ccc;
 padding: 4px;
 border-radius: 4px;
}
/* Assuming you added a class 'mytextbox' for textbox, this adjusts textbox style */
.short-url-fe .mytextbox {
 width: min(20rem, 70%);
 box-shadow: 2px 2px 4px 1px #ccc inset;
 padding: .5rem 4px;
}
/* and assuming you added a class 'mycopybutton' for button, this adjusts button style */
.short-url-fe .mycopybutton {
 background-color: lightblue;
 color: darkblue;
}
</code></pre>

Short URL FE

Show a Short URL for all of your blog posts and optionally for pages

akrabat

The Shorter Links WordPress plugin overrides the default WordPress 
“shortlink” URL with one that has a custom text in it. You can also set a 
different base URL.
A custom field called “Shorter link” is created once a post is saved, 
so that you can change the shortlink to a more memorable set of 
characters.
The choice of base URL to use for the short link can be configured within 
Settings->Shorter Links.
Related Links:
<ul>
<li><a href="http://akrabat.com/shorter-links" rel="nofollow ugc">Plugin home page</a></li>
</ul>
<h3>Licence</h3>
This plugin is licensed under the <a href="http://akrabat.com/license/new-bsd" rel="nofollow ugc">New BSD license</a>.
<h3>History</h3>
2.1.0 – 8 August 2015 
Rework to look for the shorter link after WordPress has done its processing. This 
means that a shorterlink that represents a date won’t affect an archive list.
2.0.6 – 8 August 2015 
Ensure that the short_link is correct when using a post id.
2.0.5 – 8 August 2015 
Updated Tested up to 4.3
2.0.3 – 9 July 2012 
Bug fix so that archives work.
2.0.2 – 23 June 2012 
Fall back to REQUEST_URI if there’s nothing interesting in $query_vars.
2.0.1 – 20 June 2012 
Updated to handle 4 digit short links that look like a year to WordPress.
2.0.0 – 21 November 2010 
Updated to be WordPress 3.0 or above, so we only need to hook into the WordPress 
shortlink system
1.8.2 – 21 November 2010 
Fix permissions issue on settings page. This is the last version that works 
on WordPress 2.9.x or earlier.
1.8.1 – 7 September 2010 
Bug fix to remove a warning.
1.8 – 1 September 2010 
use shortlink rather than shorturl for WordPress less than 3. 
For WordPress 3 or higher, hook into the new shortlink system. 
Fix the admin page so that it displays in WordPress 3.
1.7 – 11 Feburary 2010 
Handle failures better.
1.6 – 10 January 2010 
Update version number in correct places so that the WP plugins system notices the update.
1.5 – 29 December 2009 
Support permalinks that start with /%category%/
1.4 – 14 April 2009 
Support rel=”shorturl” as per <a href="http://sites.google.com/a/snaplog.com/wiki/short_url" rel="nofollow ugc">Robert Spychala’s Short URL Auto-Discovery proposal</a>.
1.3 – 14 April 2009 
Add support for setting the base URL. Patch by <a href="davemastergeneral@gmail.com" rel="nofollow ugc">Dave Marshall</a>.
1.2 – 13 April 2009 
Only send the <code>Link</code> HTTP header as recommended by <a href="http://shiflett.org/blog/2009/apr/a-rev-canonical-http-header" rel="nofollow ugc">Shiflett</a>.
1.1 – 13 April 2009 
Fixed output of HTTP headers. Patch by <a href="http://bethesignal.org/" rel="nofollow ugc">Jeff Waugh</a>.
1.0 – 11 April 2009 
Initial release.

Shorter Links

Override the default WordPress "shortlink" URL with one that has a custom text in it. You can also set a different base URL.

Short URL FE vs Shorter Links