andOTP implements time-based one-time passwords (TOTP) as specified in RFC 6238 (HOTP support is currently in beta testing). Simply scan the QR code and log in with the generated 6-digit code.
FEATURES
- Free and Open Source
- Requires minimum permits:
 - Camera access to scan QR codes
 - Storage access for database import and export
- Encrypted storage with two backends:
 - Android KeyStore (can cause problems, please only if absolutely necessary)
 - Password / PIN
- Multiple backup options:
 - Simple text
 - Password protected
 - OpenPGP Encryption
- Minimalist and elegant material design with three different themes:
 - Light
 - Dark
 - Black (for OLED displays)
- High usability
- Compatible with Google Authenticator
Backup copies:
To keep your account information as secure as possible and the OPT only stores it in encrypted data files. There are two encryption methods that can be used: the Android KeyStore or a Password/PIN.
KeyStore is a component of the Android system for the secure storage of cryptographic keys, the advantage of this approach is that the key is kept separate from application data and, as an additional advantage, can be backed up by hardware cryptography (if your device supports it). However, due to this separation, backups with third-party applications such as Titanium Backup cannot be used if this method is chosen. These applications only back up encrypted data files and not the encryption key, which makes them useless. In this case, you will have to rely on andOTP's internal backup functions!
The KeyStore is known to cause many problems, so please use it only if absolutely necessary and you know what you are doing. In that case, make sure to make regular backups in case something goes wrong. It is always recommended to use a password or PIN instead!