This plugin changes the error messages when a keyword or url already exists. If a keyword already exists, the error message will display the URL for that keyword. If the URL already exists, the share box will be displayed.
This plugin has a conflict with the Expiry plugin. If you have the Expiry plugin installed and activated, you get a white screen when you try to activate this plugin.
But if you deactivate Expiry plugin, this plugin activates with no problem.