Pros of FreeOTP Android

• Open-source and fully auditable, enhancing trust and security
• Supports a wider range of token types, including HOTP and TOTP
• More frequent updates and active community involvement

Cons of FreeOTP Android

• Less intuitive user interface compared to Google Authenticator
• Fewer built-in features for backup and account recovery
• Smaller user base, potentially leading to slower bug detection

Code Comparison

FreeOTP Android (Kotlin):

override fun onOptionsItemSelected(item: MenuItem): Boolean {
    return when (item.itemId) {
        R.id.action_add -> {
            startActivity(Intent(this, AddActivity::class.java))
            true
        }
        else -> super.onOptionsItemSelected(item)
    }
}

Google Authenticator (Java):

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case R.id.add_account:
            startActivity(new Intent(this, AddAccountActivity.class));
            return true;
        default:
            return super.onOptionsItemSelected(item);
    }
}

Both repositories implement similar functionality for adding new accounts, but FreeOTP Android uses Kotlin's more concise when expression, while Google Authenticator uses Java's traditional switch statement. FreeOTP's code is generally more modern and adheres to current Android development practices.

Pros of yubioath-flutter

• Cross-platform support (iOS, Android, desktop) using Flutter framework
• Modern UI and user experience
• Active development and frequent updates

Cons of yubioath-flutter

• Limited to Yubico hardware devices
• Smaller community and ecosystem compared to Google Authenticator
• Steeper learning curve for developers unfamiliar with Flutter

Code Comparison

yubioath-flutter

Future<void> addCredential(Credential credential) async {
  await _yubiKeyManager.addCredential(credential);
  _refreshCredentials();
}

google-authenticator

public void addAccount(String secret, String issuer, String accountName) {
    AccountDb.OtpType type = AccountDb.OtpType.TOTP;
    Account account = new Account(secret, issuer, accountName, type);
    mAccountDb.add(account);
}

The yubioath-flutter code uses Dart and async/await for adding credentials, while google-authenticator uses Java and a more traditional object-oriented approach. yubioath-flutter's implementation is more concise and modern, leveraging Flutter's asynchronous programming model.

yubioath-flutter focuses on Yubico hardware integration, offering a specialized solution for users of Yubico devices. google-authenticator, on the other hand, provides a more general-purpose TOTP implementation that works across a wider range of devices and use cases.