Here is some additional information that may prove useful in your mastery of Google Plus: third-party websites and useful extensions running on Google's Chrome and other browsers.
Google has yet to widely release the Application Programming Interface (API) to Google+, but there are still third-party (not associated with Google) sites that enhance using Plus. The following are a few of these sites:
FindPeopleOnPlus.com: A directory site indexing over sixteen million Plus users now and ranking the top people. Mark Zuckerberg, a founder of Facebook, ironically has more followers than Larry Page and Sergey Brin, both founders of Google. Check it out at http://findpeopleonplus.com.
SocialStatistics.com: Indexes ...