Ask HN: Recommended two-factor authenticator app for personal use?

I haven't really looked into authenticator apps before, but with the increases in SIM-jacking I think it's time. I don't use Google, so Google Authenticator is out. I use Duo at work; can you use that for arbitrary personal services? Are there others apps that come recommended?

Also, just general questions: are these apps usually free (if not, free isn't a hard requirement)? Is there some standard, or does each service only support a subset of apps? What happens if you lose your phone?

Any info is appreciated

Edit: One more question: I see rumblings from some people about using password managers as an alternative to 2FA apps. Is that a valid strategy? Does one make the other redundant?

Edit 2: I found this excellent deep-dive on the overall mechanism and the major players: https://arstechnica.com/information-technology/2020/05/choosing-2fa-authenticator-apps-can-be-hard-ars-did-it-so-you-dont-have-to/ Based on this I'll probably go with Authy

Bitwarden

Even if you don’t use Google, you can use their Google Authenticator app.

Aegis, it's FOSS and supports encrypted backups. Migrating to a new device is trivial.

Best of all: it even supports 7 digit TOTP that previously required Authy (I think Cloudflare and HumbleBundle use this variant).

https://github.com/beemdevelopment/Aegis

Pebble-authenticator.

2FA is a killer application for a smartwatch.

Equally awesome are barcodes, replacing membership cards.