Do Not Use. Questions about using Google Authenticator are off-topic, as this app is installable for Android, iPhone and iPad. Questions about this app might be on topic in https://android.stackexchange.com/, https://apple.stackexchage.com, and https://security.stackexchange.com.
Google Authenticator is a cross-platform application for Android, iPhone and iPad that implements two-factor authentication by generating one-time passwords for logging in or authenticating an app with a Google account.
Most questions about this app are off-topic in Web Applications SE unless the core of the question is about using a web application, like the Google Accounts 2-Step Verification guided web set up, rather than using Google Authenticator (installing, setting up, etc.)
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