We usually reply within a couple of days.
No — and that's by design. Your master password derives the encryption key and never leaves your device, so nobody (including us) can recover it. If you're still signed in on another device, export a backup there and restore it with a new password.
Either enable iCloud Sync on both devices, or export an encrypted backup
(Settings → Export Encrypted Backup), AirDrop or copy the .otpvault file to the new
device, and open it with OTPeek.
Yes — scan the QR codes from Google Authenticator's "Transfer accounts" export
(otpauth-migration links are supported), scan any standard otpauth:// QR,
or add secrets manually.
TOTP codes depend on the clock. Make sure your device time is set automatically — a drift of more than about 30 seconds produces wrong codes.
Open the app once after installing so the widget can read the shared vault, and check that the account you want is favorited (widgets show favorites first).
Yes — the entire app (Rust core, iOS/macOS, Windows) is at github.com/jiunbae/OTPeek. Audits and pull requests welcome.