Michal Ozogan

Googles+ widget which provides you public post from your timeline. It shows your statuses, images, videos, links and albums. You need create your google plus app (https://code.google.com/apis/console/b/0/?pli=1) and enter your api + your profile ID. The are also some customizations like size of your profile image, number of showed posts and max width of images.

Easy Google+ Widget

Googles+ widget which provides you public post from your timeline.

Mervin Praison

This plugin helps you add Google authorship markup to your WordPress site, allowing your Google Plus profile picture to appear in Google Search results.
Features: 
* Easy 4-step setup process 
* Multiple author support 
* Multisite compatible 
* Shortcode support

WP Google Authorship

Nice

Google Plus Profile Picture appear in Google Search. Very Easy to implement. Including Google authorship for multiple authors and multisite.

Easy Google+ Widget vs WP Google Authorship