Password managers and one-time-code apps are listed together here. AliasVault combines a password manager with email aliases, Bitwarden publishes its iOS app, and KeePassium and Strongbox both open KeePass databases. Pass is a client for the pass command line tool, and MasterPassword derives passwords from a master secret instead of storing them.
For two-factor codes, Authenticator, FreeOTP and OakOTP are small native apps on the App Store. Raivo OTP, MiniKeePass and Encryptr are marked as unmaintained. Before trusting any of these with real credentials, check that the app has recent commits and a public security policy or audit. For developers, these projects show how to use the Keychain, Face ID and the AutoFill credential provider extension.