1. Best rated Two-Factor Authentication smartphone app for consumers, simplest 2fa Rest API for developers and a strong authentication platform for the enterprise.

  2. LoginTC is a simple, secure 2-Factor Authentication solution.

  3. YubiKey provides security solutions for strong two-factor authentication using U2F, OTP, PIV, and more.

  4. Clef is secure two-factor with no passwords or tokens.

  5. Rublon is a multi-factor authentication for WordPress.

  6. WiKID is an on-premise two-factor authentication solution.

  7. UNLOQ offers Multi-Factor Authentication, Transaction authorization, and Data Encryption solutions for Businesses and Organisations.

  8. privacyIDEA is an enterprise ready, open-source multi factor authentication system.

  9. Authenticator Plus generates 2-step verification codes and lets you synchronize your accounts.