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

Josh Betz

Changes the Short URL and the Twitter Tools URL for each post on your site using a custom, shortened domain and a base-36 encode of the post ID.

JB Shortener

Changes the Short URL and the Twitter Tools URL for each post on your site using a custom, shortened domain and a base-36 encode of the post ID.

Short URL FE vs JB Shortener