SeedProd

John Turner

Easily setup a full text site search powered by Google.
Normally to setup a Google Custom Search on your site you have to sign up on Google and create the search index. This plugin will do it automatically using Google’s <a href="http://www.google.com/cse/docs/cref.html" rel="nofollow ugc">Linked Custom Search Engines</a>
<ul>
<li><a href="http://www.seedprod.com/blog/" title="SeedProd Demo" rel="nofollow ugc">View a Live Demo »</a></li>
</ul>
<h3>Features:</h3>
<ul>
<li>Works with any WordPress Theme</li>
<li>No need to setup a Google Custom Search</li>
<li>No Google account required </li>
<li>Search results show up on the default search result page.</li>
<li>Just add the “Google Site Search” widget to your theme.</li>
<li>Does not replace the default WordPress search. It runs along with it. Use both if you want.</li>
</ul>
This plugin is built and maintained by <a href="http://www.seedprod.com/" rel="nofollow ugc">SeedProd</a>

WordPress Google Search

Add a Custom Google Site Search with no setup. Just drag and drop a widget and you're done.

WebshopLogic

If you would like a Google search feature on your WordPress site, you only need to register to Google Custom Search, get your Google Search Engine ID, and enter it in the plugin settings page. 
Then your custom search engine is ready for use, just put the new Google search box widget on the sidebar, and enjoy it!
In this way the plugin enables you to insert Google search into your website, or a collection of websites easily. You can search both web pages and images. 
You can define if you want to search only on your site (or given sites), or the entire web. 
It is possible to customize your search features, the look and feel (layout, themes, custom colors and fonts, thumbnails), and much more. 
All these settings can be specified on the Google Custom Search Engine admin site: <a href="https://www.google.com/cse/" rel="nofollow ugc">https://www.google.com/cse/</a> 
Your changes will appear instantly on your site automatically.
After you registered to Google Custom Search Engine and get your Google Search Engine ID, you need to enter the ID in the plugin settings page: Settings -> WP Google Search 
Use WP Google Search widget or [wp_google_searchbox] shortcode to place search box on your site.
Search results can be displayed on a normal page or in a popup window. Use Full Width layout or Overlay (popup) layout on Google Custom Search Admin site to setup it.
It does not require any coding or other complicated operation.
Please find more information in the product documentation: 
<a href="https://webshoplogic.com/wordpress-google-search-plugin-for-free/" rel="nofollow ugc">WP Google Search Documentation</a>
<h4>Available languages</h4>
<ul>
<li>English</li>
<li>Spanish – translated by Ogi Djuraskovic – <a href="http://firstsiteguide.com" rel="nofollow ugc">http://firstsiteguide.com</a></li>
<li>Serbian – translated by Ogi Djuraskovic – <a href="http://firstsiteguide.com" rel="nofollow ugc">http://firstsiteguide.com</a></li>
<li>Portuguese (BR) – translated by Gabriel Froes</li>
<li>Swedish – translated by Tobias – <a href="http://ComClick.se" rel="nofollow ugc">http://ComClick.se</a></li>
<li>Danish – translated by Alexander Leo-Hansen – <a href="http://alexanderleohansen.dk" rel="nofollow ugc">http://alexanderleohansen.dk</a></li>
<li>Russian – translated by Timofeev Ilya</li>
</ul>

WP Google Search

...auto-integration with the built in WordPress search form. That way themes wouldn't need as much updating, no additional widget, etc., since most themes don't have the search box as a widget, but as part of the navigation.

Does what is says but could be better with...

This plugin gives a very simple way to integrate Google Search into your WordPress site.

WordPress Google Search vs WP Google Search