Yes, modern smartphones have built-in passkey support:
iPhone (iOS 16+):
- Use the built-in "Passwords" feature (iCloud Keychain)
- No third-party app needed
- Automatically syncs across all your Apple devices
Android (Android 9+):
- Use the built-in Google Password Manager or Samsung Pass
- No third-party app needed
- Automatically syncs across all your Android devices and Chrome browsers
Simply follow the software passkey registration instructions above using the QR code method, and your operating system will handle the passkey storage automatically.