1. On new phone, install Google Authenticator.
2. Get Started > Import existing accounts?
3. On old iPhone, open Google Authenticator > More (...) > Export accounts > Continue.
4. Touch ID for "Authenticator": [Fingerprint]
5. Select all accounts > Export
6. On old phone, display "Scan QR code x of y" with QR code
7. On new phone: Scan QR code.
8. Hold new iPhone to scan QR code on old phone > Scanned QR code x of y: Continue
9. On old phone, swipe left to reveal 2nd QR code > Hold new iPhone to scan 2nd QR code on old phone
10. On new phone, it'll displayed, x accounts imported: OK
URL: https://support.google.com/accounts/answer/1066447
