It mainly has 3 types of reports:

The Search Impact Report shows the affect of +1 on organic search traffic.

The Activity Report shows the number of times the website pages have been given a +1(on the website as well as other pages).

The Audience Report provides the geographic and demographic information about the Google users who have given a +1 to your website.

Not only this, you can also find out how your website content is being shared, using +1 and other buttons.

• The Social Engagement Report concentrates on the visitor's behaviour.
• The Social Actions Report helps you track down the number of +1, Tweets etc, taking place on the website.
• The Social Pages report helps you find out the pages which are receiving the highest number of social actions.

Google will automatically enable Social Plugging Tracking, if +1 buttons have been added to your website (and also if you are using the latest Google Analytics Tracking code - default version).