Google Authenticator is a particularly popular smartphone application that can be used as a token for many two factor authentication (2FA) systems by generating a time-based one time password ...

Once you have the key it is easy to send the public key ... There are several options, but the one I’ll use is from the Google Authenticator application. You can get the application for Apple ...

Google's two-factor authentication application for mobile devices. After logging into a site that uses Authenticator, users receive a phone message with a unique numeric code for that login session.