Looking for logging into the Google Sign In Swift site and are not getting the correct working link for it? In such a case, you can use the links given here by searching your desired login page in the search box. If the page is present on our website then you will get all the links related to the Google Sign In Swift site. After that you can login as usual with your login credentials.
https://developers.google.com/identity/sign-in/ios/
https://firebase.google.com/docs/auth/ios/google-signin?hl=ja
https://qiita.com/shin1ogawa/items/0700c443262ba3d444a7
https://dev.classmethod.jp/smartphone/iphone/google_singin_tutorial1/
https://medium.freecodecamp.org/google-sign-in-sdk-with-swift-for-ios-914316e0ade8
https://stackoverflow.com/questions/43439542/how-to-use-google-sign-in-api-with-swift
https://stackoverflow.com/questions/34368613/custom-google-sign-in-button-ios
https://www.simplifiedios.net/google-sign-integration-ios/
http://grandbig.github.io/blog/2015/09/13/google-sign-in/
http://blogs.innovationm.com/google-signin-integration-in-swift-3-0/
http://chicketen.blog.jp/archives/68293380.html
https://teratail.com/questions/68339
http://swiftdeveloperblog.com/firebase-social-authentication-signin-with-google-in-swift/