This plugin will only add datalist (it's a HTML5 feature) to the search field. It is not a live search.
The idea for this plugin is to provide or guide your user what to search or in better words, what type of content or keywords they can search.
Other thing is,
You know your site better and also expect users with the same field. Means you can set predefined keywords example: for cooking Q&A site
How to cook