In this article, we explored the Google+ Sign-In APIs and learned how to authenticate users for an application, load their profile information, and share social actions on their behalf. We also briefly touched on how to manage their information when the user no longer wants to use your site.
Google+ Sign-In is a powerful authentication method that not only provides user identity verification but also gives you tools to make your application more viral. There are many additional features you get for free once you add Google+ Sign-In to your site—far too many to cover in one article (for example, giving users the option to install your Android app when they log in to your site). I strongly encourage you to check the following links to discover what other associated services can make your site more awesome.
You can read more about Google+ Sign-In by visiting https://developers.google.com/+/web/signin. The source code for this article is available at https://github.com/jwill/informit-articles/tree/master/Google%2BSignIn.