GoogleSignInApi Api interface for Sign In with Google. 
GoogleSignInOptionsExtension An interface for API specific extension for GoogleSignInOptions


GoogleSignIn Entry point for the Google Sign In API. 
GoogleSignInClient A client for interacting with the Google Sign In API. 
GoogleSignInResult GoogleSignInResults are Result implementations that potentially contain a ERROR(/GoogleSignInAccount)
GoogleSignInAccount Class that holds the basic account information of the signed in Google user. 
GoogleSignInStatusCodes Google Sign In specific status codes, for use in Status#getStatusCode()
GoogleSignInOptions GoogleSignInOptions contains options used to configure the Auth.GOOGLE_SIGN_IN_API
GoogleSignInOptions.Builder Builder for GoogleSignInOptions,  
RevocationBoundService Handles Google Sign-In user revocation.