Instagram & Pinterest

Actually I just added it myself. Pretty easy to do.
First you need to download a set of icons (png) sizes 16,24,32,48, and 64.
All icons have to have the same name and upload them to the wp-content/plugins/the-social-links/icons directory in your WP hosted directory.

First make a copy of the “the-social-links/the-social-links.php” file in case you need the backup.
Then open the the-social-links/the-social-links.php file.
You will see the list of services start after $social_networks = array(
Copy one of the services listed, create a new line and paste the copied information.
Change the lowercase name (first one displayed) so that it matches the name of the icon file uploaded.
Change the second name to the name of your service which is displayed in the settings form when you add the URL.
‘pinterest’ => ‘Pinterest’,
Save the file, and reactive your plugin if required. That was it.