Additional Tag Plugin

I need help on Additional Tag plugin. After the installation of Additional Tag plugin, I went to admin's dashboard, couldn't see anywhere that shows the features for this plugin. I need to see which tag from which video service is allow to be available for users to use.

Under site admin >> options, there is no sign of additional tag is installed. But as a test user, I add Youtube's embedded code in html tab for adding new post, it works automatically. I'm not clear about this plugin. I feel more comfortable if I have control over this plugin since it's stripping javascript tags which is a dangerous thing if a user can enter just about any javascript tag!