andOTP - OTP Authenticator

andOTP is a mobile application that allows users to generate Time-based One-time Passwords (TOTP) according to the specifications outlined in RFC 6238. This means that users can use the app to generate a unique 6-digit code that can be used for login purposes. The app also has beta support for HOTP. To use the app, users simply need to scan a QR code and then use the generated code for login.

The app is free and open-source, meaning that it is available for anyone to use and modify. It only requires minimal permissions, such as camera access for scanning QR codes and storage access for importing and exporting the database. The app also offers encrypted storage with two options: using the Android KeyStore or a password/PIN.

Users also have multiple backup options to choose from, including plain-text, password-protected, and OpenPGP-encrypted. The app has a sleek and minimalistic Material Design with three different themes: light, dark, and black (for OLED screens). It is also highly usable and compatible with Google Authenticator.

To ensure the security of user account information, andOTP only stores it in encrypted data files. Users can choose between using the Android KeyStore or a password/PIN for encryption. The KeyStore offers the advantage of keeping the key separate from the app's data and can be backed by hardware cryptography. However, this method may cause problems with third-party backup apps. In such cases, users can rely on the app's internal backup functions.

andOTP is currently in beta testing, and users are encouraged to submit any bugs or feedback directly on Github. The app is fully open-source and licensed under the MIT license, with the source code available on Github. It is a fork of the OTP Authenticator app by Bruno Bierbaumer, which is no longer available on Google Play. However, the code for the original app can still be found on Github.