Ente Auth

Ente Auth stores your TOTP codes with end-to-end encrypted sync across phone and desktop — the thing Google Authenticator historically wouldn’t do safely and Authy did with a proprietary lock-in that ended badly when its desktop app was killed. Import from other authenticators is smooth, export is unencumbered, backups are yours, and the whole stack is open source from a company whose photo product runs on the same infrastructure.

A desktop authenticator is a convenience/security trade: codes on the same machine as your browser weakens the second factor somewhat — for your most critical accounts, hardware keys or phone-only is stronger. The company is small and the auth app is a free side product of their photos business, so factor that into long-horizon trust.