benjick

Add a Google+ Page button easily with this plugin. The shortcode is <code>[googlepage]</code>
Usage: 
* Smallest icon: <code>[googlepage page=YOUR_PAGE_ID]</code> 
* Medium icon: <code>[googlepage size=32 page=YOUR_PAGE_ID]</code> 
* Biggest icon: <code>[googlepage size=64 page=YOUR_PAGE_ID]</code>
In page=x where x is your Google+ Page number.

Google Plus Page shortcode

This plugin allows you to add links to a Google+ Page with simple shortcode

Skysa

Let a visitor share your pages and content with friends on Google Plus with this Google Plus One button which floats at the bottom of your pages on the Skysa App Bar. Google Plus is a social network which connects all people who have a Google account. When a user clicks a Google Plus One button on your site, they will not only share the page with their friends on Google Plus, but it will also affect Google search results for the shared page.
http://www.youtube.com/watch?v=Zj1uGXX2xrk&hd=1 
<a href="https://wordpress.org/extend/plugins/tags/skysa-apps" rel="ugc">More Skysa App plugins</a> -|||- <a href="https://wordpress.org/extend/plugins/skysa-official/" rel="ugc">Skysa App Bar Integration plugin</a>

Skysa Google +1 App

A Google +1 button which you can configure to share any page on your site.

Google Plus Page shortcode vs Skysa Google +1 App