Which is the best authenticator app for iPhone?

Google Authenticator is a long-established and popular account authentication application, trusted by many iPhone users. 

Google Authenticator is quite simple and easy to use, helping many internet users secure their accounts from issues such as hackers or forgotten passwords. 

Additionally, it can be used simultaneously on multiple devices. Users can set up Google Authenticator on multiple devices and use them in parallel. Along with that, it supports multiple platforms as it works on iPhone, iPad, and Android devices. 

Moreover, users do not actually need a Google account for the application. Although they can obviously use it with Google’s system, users can still use it with third-party services without linking their Google account to the authenticator. 

Since the system relies on entering a setup key or scanning a QR code, users should set up two-factor authentication (2FA) on a different device than the one they set up Google Authenticator on. 

How to use Google Authenticator

1. Download Google Authenticator from the App Store to your device. 
2. Log in to any service you want to enable 2FA for and set up that service. In the account settings, select the “security” section and choose “set up two-factor authentication,” although the naming of this option may vary between services or social networks.
3. If prompted by the application, users should choose to use an authentication app. They may be recommended to use certain authentication apps, so check if Google Authenticator is on the list.
4. After being provided with a QR code or authentication key, open Google Authenticator on your iPhone or iPad, and select the plus icon in the bottom right corner of the screen.
5. If a QR code is displayed on the website or app you are setting up 2FA for, choose “Scan a QR code,” then use your device's camera to scan the code.
6. Enter the account name (usually the related email address) and the key provided on the screen. Choose either Time-based or Counter-based authentication. Generally, the best choice is to leave it as Time-based.
7. You will then be asked to confirm that the authentication system is working. Enter the six-digit code that appears on your device’s screen into the application or service you are securing.
8. Once set up, you will be required to use the authentication app to generate codes to log in to services whenever you sign in.

This is very simple, as all you need to do is open Google Authenticator, find the service and account name related to it, and then read the six-digit code associated. You can also do more with Google Authenticator, such as setting it up so that you receive the same codes on multiple devices."