Apps similar to Authenticator Extension include Bitwarden, which is open source with a free version. Other options are Aegis Authenticator, Proton Authenticator, Ente Auth and Bitwarden Authenticator. You're spoiled for choice with Authenticators like Authenticator Extension: we list more than 50 alternatives for Android, iPhone, iPad, Mac and Windows.
OVault is a super simple OTP app that lets you view and manage OTPs for all your accounts. Set up OTPs by scanning QR codes with your devices Camera App, or by manually providing the OTP secret to the app.
United Kingdom
Mauth (pronounced Moth) is a Two-Factor Authentication app with support for TOTP and HOTP (coming soon) and compatibility with Google Authenticator.
Georgia
Tofu generates one-time passwords to help you protect your online accounts. These passwords are used together with your normal password when you sign into services like Google, Facebook, Dropbox, Amazon, and GitHub.
Sweden
EU
Keysmith is a token generator for your two-factor authentication (2FA) logins. It supports time and hash-based one-time passwords (TOTP/HOTP).
GermanyEU
OTP authenticator app for managing your 2FA / OTP codes on iPhone, iPad, Mac and Apple Watch.
Australia
Gnome Authenticator is a desktop 2FA code generator for Linux desktops, like Ubuntu.
CzechiaEU
An awesome two-factor authenticator based on Flutter, supports Android, Windows and Linux platforms, and supports multiple cloud backup methods such as Onedrive, Dropbox, WebDAV, S3Cloud, etc.
China
HungaryEU
LastPass Authenticator offers a unique one-tap password verification experience that no other authenticator app delivers.
United States
Protectimus Solutions provides a powerful multi-factor authentication service. We offer 2FA SaaS platform and on-premise version of the product which supports a great variety of TOTP tokens and program tokens for OTP delivery.
United Kingdom
Encrypted Windows app for managing 2FA codes with AEGIS-256 and Argon2id, supporting Windows Hello, portable use, multilingual interface, token import/export, QR code/manual entry, generic TOTP, local storage, and dark mode interface for enhanced security.
GermanyEU
GTK+ application for securely managing TOTP & HOTP tokens. Content is encrypted on disk using AES256-GCM. Master password derived using PBKDF2 with 100k iterations & SHA512 as hash algorithm. Can import encrypted backups from andOTP & Authenticator+.
ItalyEU
