Just configure the desired Google+ ID in the backend and add the widget to a sidebar.
It will allow visitors to directly add a Google+ user/page to one of their circles, right from the blog, without going to their Google+ page.
Installation:
Unpack and upload it to the /wp-content/plugins/ directory.
Activate the plugin through the 'Plugins' menu in WordPress.
Requirements:
· WordPress 2.7 or higher
What's New in This Release: [ read full changelog ]
· Changed the name of a function to prevent a fatal error from possibly being triggered.