2. Stream
0 Steam occupies the middle of three columns on the
page, users see updates from those in their Circles.
There is an input box which allows users to enter a
post. Along with the text entry field there are icons to
upload and share photos and videos. The Stream can
be filtered to show only posts from specific Circles.
-Wikipedia

3. Messenger
0 Messenger is a feature available to
Android, iPhone, and SMS devices for communicating
through instant messaging within Circles.
Additionally, users can now share photos in
Messenger between their Circles.
-Wikipedia

4. Ripples
0 Ripples, introduced on October 27, 2011, is a
visualization tool, showing how resharing activity
happens regarding a public post. One can replay the
public share's activity, zoom in on certain
events, identify top contributors, view statistics about
average chain length, the most influential people in
the chain, the language of the sharers, etc. -Wikipedia

5. Games
0 Google+ Games provides its users with a secondary
tab dedicated to popular games which users can click
and access very quickly. Users can also save their
favorite games to access them even quicker.