Proton has released Proton Authenticator, a free and open-source two-factor authentication app available across multiple platforms, including Windows, macOS, Linux, Android, and iOS. Designed with a focus on privacy and security, it generates time-based one-time passwords and offers features like encrypted backups, biometric app locking, and easy import/export options. This new tool aims to provide a secure alternative to existing authentication apps that often rely on closed-source models and user lock-in.