15. Google+ – Developer Google
Google+ is a social networking and identity service that is owned and operated by Google Inc. Google has described Google+ as a “social layer” that enhances many of its online properties, and that it is not simply a social networking website, but also an authorship tool that associates web-content directly with its owner/author. It is the second-largest social networking site in the world after Facebook. 540 million monthly active users are part of the Identity service side, by interacting socially with Google+’s enhanced properties, like Gmail, +1 button, and YouTube comments. In October 2013, Google counted 540 million active users, of which 300 million users are active in “the stream”.