Apsara Aruna

This is customized your search form to the full screen search box.
How to use it 
*Only you have to do after the installation, add custom link to you menu and type url to ‘#search’. you can put Link text as you wish.
Also see my other plugins 
* <a href="https://wordpress.org/plugins/widget-youtube-subscribtion/" title="Easy Subscribe Button Widget" rel="ugc">Easy Subscribe Button Widget</a> 
* <a href="https://wordpress.org/plugins/embed-page-facebook/" title="Easy Embed Page Widget" rel="ugc">Easy Embed Page Widget</a> 
* <a href="https://wordpress.org/plugins/browser-scroll-bar/" title="Browser Scroll Bar" rel="ugc">Browser Scroll Bar</a>

Easy Full Screen Search

This is customize you search form to full screen search box.

Arefly

Sometimes when user are using the search function of your blog. They may not know the full string of they want to search.
And this plugin will add a Search Keyword Hint (get hints from all tags) on the search form of your site.
So that user can find the things they want to search more easily.
Live Demo: <a href="http://www.arefly.com/" rel="nofollow ugc">Click Here</a> (Try enter any word in the search box.)
中文介紹請看<a href="http://www.arefly.com/wp-search-auto-match/" rel="nofollow ugc">這裏</a>

WP Search Auto Match

Add Search Keywork Hint like Google Search to your blog's search form.

Easy Full Screen Search vs WP Search Auto Match