Pros of andOTP

• More feature-rich, including categories, tags, and advanced backup options
• Active development with frequent updates and bug fixes
• Supports custom icons for OTP entries

Cons of andOTP

• Slightly more complex user interface, which may be less intuitive for some users
• Larger app size due to additional features

Code Comparison

FreeOTP Android (Java):

public class Token {
    private String issuer;
    private String label;
    private String image;
    private String type;
    private String algorithm;
}

andOTP (Kotlin):

data class Entry(
    var type: OTPType,
    var algorithm: HashAlgorithm,
    var issuer: String,
    var label: String,
    var tags: MutableList<String> = mutableListOf()
)

The code snippets show that andOTP uses Kotlin and includes additional fields like tags, while FreeOTP Android uses Java and has a simpler structure. andOTP's implementation allows for more flexibility and organization of OTP entries.

Both projects are open-source and provide secure two-factor authentication solutions for Android devices. FreeOTP Android offers a simpler, more straightforward approach, while andOTP provides a feature-rich experience with additional customization options. The choice between the two depends on the user's preferences for simplicity versus advanced features.

Pros of 2fas-android

• More feature-rich, including backup and sync options
• Modern UI design with customizable themes
• Supports a wider range of token types and algorithms

Cons of 2fas-android

• Larger app size and potentially higher resource usage
• More complex codebase, which may lead to longer development cycles
• Requires more permissions, which some users may find concerning

Code Comparison

FreeOTP-Android uses a simpler approach for token generation:

override fun generateOTP(): String {
    return TOTP(secret, digits, algorithm).generateOTP()
}

2FAS-Android employs a more complex system with additional features:

fun generateTOTP(secret: String, time: Long, digits: Int, algorithm: HashAlgorithm): String {
    val hmac = when (algorithm) {
        HashAlgorithm.SHA1 -> HmacSHA1()
        HashAlgorithm.SHA256 -> HmacSHA256()
        HashAlgorithm.SHA512 -> HmacSHA512()
    }
    return TOTPGenerator(hmac, digits).generate(secret, time)
}

Both projects are open-source Android authenticator apps, but 2FAS-Android offers more features and customization options at the cost of increased complexity and app size. FreeOTP-Android focuses on simplicity and minimal permissions, making it a lighter-weight option for basic two-factor authentication needs.

Pros of Aegis

• More feature-rich, including categories, icons, and advanced filtering options
• Supports encrypted backups and multiple vaults
• Actively maintained with frequent updates and bug fixes

Cons of Aegis

• Larger app size due to additional features
• Slightly more complex user interface, which may be overwhelming for some users
• Not as widely recognized or adopted as FreeOTP

Code Comparison

FreeOTP-Android (Java):

public class Token {
    private String issuer;
    private String label;
    private String image;
    private String type;
    private String algorithm;
}

Aegis (Kotlin):

data class VaultEntry(
    var uuid: UUID,
    var type: OtpInfo,
    var name: String,
    var issuer: String,
    var icon: VaultEntryIcon?,
    var group: String?,
    var note: String?
)

The code comparison shows that Aegis uses Kotlin and has a more comprehensive data structure for storing token information, including additional fields like UUID, group, and note. FreeOTP-Android uses Java and has a simpler Token class with basic information.

Pros of Google Authenticator

• More widely recognized and trusted brand
• Supports transfer of accounts between devices
• Includes a QR code scanner for easy account setup

Cons of Google Authenticator

• Closed-source, which may raise privacy concerns
• Less frequent updates compared to FreeOTP
• Limited customization options

Code Comparison

FreeOTP Android:

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:

@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, with FreeOTP using Kotlin and Google Authenticator using Java. The code structure is comparable, with minor syntax differences due to the programming languages used.