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 use Authenticator on Linux. I’m not sure what OS you use, but perhaps there’s another, TOTP is a pretty easy protocol to implement (it’s basically just a hash of a key and timestamp).
I would like an app for desktop and phone/tablet that are syncing, just like Authy did, before they abandoned the desktop app.
So, for me that means: iOS/iPadOS and macOS