A few of you have already found this: good find guys!
We know that signing in is a barrier for all kinds of software, especially when emails are involved. To make signing in to your apps faster and easier, we’ve added a new Sign in with Google option in the privacy settings. Users of your app will be able to use their Google account to sign in to your app—we automatically pick up their name and email address when your users choose this Sign In method.
Sign in with Google is available for apps with the “Public with email”, “Email whitelist”, or “Org members only” Sign In methods. Just check “Allow sign in with Google account” in the Privacy settings and you are good to go.
There is one caveat at the moment: due to the way that Google implements third-party sign-in, your users will see that they are using a Glide app.