When considering performance speed, you may want to keep JS scripts organized beneath your overall page HTML. This allows most of the DOM (Document Object Model) to finish loading before running any dynamic scripts.
This plugin greatly speeds up your site loading by forcing the scripts into the footer. Set it and forget it!
CAUTION: A script can be designed in such a way that it works only when placed in a header. If a plugin or a theme implements such a script, your site may not function correctly when the script is forced into a footer, or it may not display at all. If this happens, simply remove this plugin.