URL Shortener handled by your WordPress site itself.
Upload 'self-shortener' directory into '/wp-content/plugins/' directory.
Activate Self Shortener plugin through the 'Plugins' menu in WordPress.
Setup plugin using Self Shorterner menu.
To uninstall Self Shortener plugin, Deactivate and Delete from Plugin menu.
Warning: When plugin deleted, all related data (shorten URLs) are also deleted.