Google Authenticator - Google Authenticator is a multifactor app for mobile devices.
andOTP - andOTP is a two-factor authentication App for Android 4.4+
OTP Auth - The app for calculating one-time-passwords on iPhone and iPad.
Microsoft Authenticator - One app to quickly and securely verify your identity online, for all of your accounts.
Authenticator - Authenticator is a simple, free, and open source two-factor authentication app.
Authy - Best rated Two-Factor Authentication smartphone app for consumers, simplest 2fa Rest API for developers and a strong authentication platform for the enterprise.