Google Authenticator - Google Authenticator is a multifactor app for mobile devices.
andOTP - andOTP is a two-factor authentication App for Android 4.4+
Duo Security - Duo Security provides cloud-based two-factor authentication. Duo’s technology can be deployed to protect users, data, and applications from breaches, credential theft, and account takeover.
Aegis Authenticator - Aegis Authenticator is a free, secure and open source app to manage your 2-step verification tokens...
Authy - Best rated Two-Factor Authentication smartphone app for consumers, simplest 2fa Rest API for developers and a strong authentication platform for the enterprise.
Authenticator Plus - Authenticator Plus generates 2-step verification codes and lets you synchronize your accounts.