Ente Auth - The Free Authy Replacement for Your Mac and iPhone
If you miss the Authy 2FA desktop app, and you would rather not
use Apple Passwords, since if you were to lose access to your Apple
account, you would lose access to all your codes, Ente Auth is a free and open-source
option. You have the option to create an account if you want to sync
your codes between devices, or you can skip that if you just want to use
it on a single device.
The desktop version of Ente Auth has some nice features I haven't seen elsewhere. Not only does it show you the current 2FA code for your app, it also shows you the next code in the sequence. This eliminates the aggravating wait for the codes to change when there are only a few seconds left in the lifetime of the current code. You can also configure the desktop app to open directly to the search field, so you can immediately begin searching for the code you need.
It can be a hassle to set up a new authenticator, since you have to manually add sites. Most do not allow you to use more than one app to do 2FA. Still, it is a one-time chore and worth it for the convenience of having a secure desktop app with end-to-end encryption.
Thanks to Justin Pot for his article on Lifehacker about Ente Auth.