Duo mobile Alternatives

andOTP is a two-factor authentication App for Android 4.4+

Aegis Authenticator is a free, secure and open source app to manage your 2-step verification tokens...

The app for calculating one-time-passwords on iPhone and iPad.

Authenticator is a simple, free, and open source two-factor authentication app.

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

Tofu Authenticator is an open-source easy to use two-factor authentication app that lets you secure your accounts with one-time passwords.

TOTP Authenticator app makes it easier to setup and manage your 2-factor authentication accounts and tokens. The app allows you to add extra security to your accounts and protects them from hijacking. Available for iOS and Android.

freemium $6.0 / One-off

GTK+ application for securely managing TOTP & HOTP tokens.

Raivo OTP is an open-source two-factor authentication app that lets you create a one-time password for your online accounts.

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

A trusted open-source Authenticator. Formerly known as SmartWatch2 Authenticator free.

Invantive Authenticator is a two-step verification solution for use with TOTP-protected websites...

Elegant 2FA (2 Factor Authentication) solution for iOS and MacOS