Bitwarden Authenticator is a standalone app that is available for everyone, even non-Bitwarden customers.
In its current release, Bitwarden Authenticator generates time-based one-time passwords (TOTP) for users who want to add an extra layer of 2FA security to their logins.
There is a comprehensive roadmap planned with additional functionality.
Available for iOS and Android
I don’t think it caches the password. Rather a decryption key is derived from your password and is used to unlock the encrypted blob.
What I meant is that is caches the password database for offline use.