The company has also integrated its search engine into the social network and has expanded its Hangouts video-chat feature to mobile phones and broadcasting applications.
The Hangouts feature allows up to nine people to link together and chat to each other via video. It obviously supports Android phones and tablet computers but also links to the Apple iPhone and iPad.
Google says that users can now host an online broadcast using this feature to record a session and broadcast it live for public access online. Black Eyed Peas frontman will.i.am will hosted the first "Hangout on Air" for Google.
Although the company has not said how many people joined Google +, analysts estimate that it might have 25-million users in the three months it has been operating, despite being by invitation only.
However, analysts have been sceptical about the value of Google + and its ability to take on Facebook in the social networking arena. Hardly surprisingly, Facebook founder Mark Zuckerbecker is a member of Google+, which one would expect given Facebook's keen propensity to keep abreast of developments among its competitors.
