LastPass Authenticator is a mobile application designed to enhance online security by providing two-factor authentication (2FA). It generates time-based one-time passwords (TOTPs) that users enter alongside their regular passwords when logging into accounts. This extra layer of security helps protect sensitive information from unauthorized access. The app is compatible with various online services and can be used with accounts that support 2FA. Users can easily set it up by scanning a QR code or entering a setup key. Additionally, LastPass Authenticator offers backup and recovery options to ensure users can access their accounts even if they lose their device.