Authy - Best rated Two-Factor Authentication smartphone app for consumers, simplest 2fa Rest API for developers and a strong authentication platform for the enterprise.
LoginTC - Simply Strong Two-Factor Authentication LoginTC is best in class. Effortless Administration. Intuitive User Experience. Cost-effective solution for all organizations.
Microsoft Authenticator - One app to quickly and securely verify your identity online, for all of your accounts.
DIGIPASS - DIGIPASS offers two-factor authentication solutions for mobile applications.
Aegis Authenticator - Aegis Authenticator is a free, secure and open source app to manage your 2-step verification tokens...
FreeOTP - Open source implementation of the two-factor authentication HOTP and TOTP schemes.