So, you've built a Google Drive app with the latest HMTL5 technologies. Now you want to integrate Google+ sign-in into said app to provide a secure experience for your users. The Google Developer team has your back with a new tutorial:
I'm sure you heard about Google+ Sign-in. It's simple, it's secure, and it prohibits social spam, and it can be used in your Drive app! Join us today to learn how to integrate Google+ Sign-In with your Drive app and how you can use it to authorize your users.