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
Aegis encrypts it with a password, then you copy it somewhere. It’s just a set of keys and you can have as many copies as you want (I have three, one phone and two desktops).