Simple GTK+ software to generate OTPs (TOTP and HOTP)

 OTPClient is GTK+ software for two-factor authentication
 that supports both Time-based One-time Passwords (TOTP)
 and HMAC-Based One-Time Passwords (HOTP).
 .
 Features:
  - Support both TOTP and HOTP.
  - Support setting custom digits (between 4 and 10 inclusive).
  - Support setting a custom period (between 10 and 120 seconds inclusive).
  - Support SHA1, SHA256 and SHA512 algorithms.
  - Support for Steam codes.
  - Import encrypted Authenticator Plus backup.
  - Import and export encrypted and/or plain andOTP backup.
  - Import and export plain FreeOTPPlus backup (key URI format only).
  - Import and export plain Aegis backup (plain json only).
  - Local database is encrypted using AES256-GCM.
     * Key is derived using PBKDF2 with SHA512 and 100k iterations.
     * Decrypted file is never saved (and hopefully never swapped) to disk.
       While the app is running, the decrypted content resides
       in a "secure memory" buffer allocated by Gcrypt.