But since the launch, Google has "integrated" a dozen more major products into Google+, turning them into de facto features. This process starts with a minor integration and evolves into a major one.
The +1 button, which preceded Google+, was integrated into the service Aug. 24. When you find a +1 button on any website, clicking it offers a share box for publishing a link on Google+. These +1 shares are called "Snippets" by Google.
The company integrated Google Maps on Sept. 14, adding Snippets from that service for publishing on Google+. Maps users can share Snippets of driving directions, hotel information and other Maps data with their Google+ circles from Maps.
On Sept. 20, Google announced the ability to do Google Docs screen-sharing on Google+ Hangouts. It also announced a Search capability, which appears to be a subset of Google Search and which uses all the standard Google Search operators for finding posts on Google+.
Google announced that Chrome apps were getting the Google+ treatment Oct. 25. When Plus members review apps, their profiles are linked from the review.
On Oct. 31, Google integrated its RSS reader, Google Reader, into Google+, replacing that service's social features with those on Google+, for example replacing reader "friending" and "following" with Google+ "circling."
On Nov. 3, Google rolled out Google+ integrations with YouTube and Chrome. Google+ always supported YouTube, but now it has a dedicated YouTube button that enables quick searches of the video service, which then plays videos in a pop-up window. Google also announced a Chrome extension for adding +1 to any Web page, even if the site owner hasn't implemented the button.
On Nov. 16, Google rolled out its previously announced Google Music service as a music sharing service via Google+.
Google announced a redesigned Google bar that will grace the top of its biggest products, including Search, News, Maps, Translate, Gmail and many others. The new bar unifies these services with Google+, with sharing and notifications always visible and just a click away.
On Dec. 1, Google further integrated YouTube, enabling users to link their YouTube accounts to their Google+ profiles.
And most recently, on Dec. 8, Google announced major additional integrations with both Gmail and Contacts. Now, when you get email from Google+ users, you can see their most recent posts shared with you or made public by them on the right side of the email, with an option to circle them and see their contact information if they've shared it publicly.
You can also sort email with Circles. For example, you can tell Gmail to show email only from people in your "Family" circle. You can also now share pictures that come as email attachments on Google+ with one click.
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