Tutorial for Google login
To integrate google sign-in into your website,create client ID on Google Developer Console by providing project name and enable google+ api in API & Auth option on the left sidebar
provide detail as
Project Name: application name
Javascript origin: http://localhost/ or http://{domain name}/
Redirect URI: http://localhost/{site-name}/callback page or http://example.com/login.php
Now to implement google login in your website, download google plus api for php from Here. Make changes in the credentials of the app in login.php and run the code.