Q: What’s The Difference Between The Trial Version And The Full Version?
A: The trial version of the program allows you to free scan your iTunes backup and preview the first digit of the password. If you want to recover all of your passwords, then you'll need to upgrade to the pro version.
Q: Why The Decryption Process Takes So Long?
A: The decryption speed is tightly related to many factors such as: the length and the complexity of the password you set, the PC performance and it's memory space, your iTunes memory space and the iOS version, etc.
In order to speed up the process, it's recommended to use "Brute-force with Mask Attack" type to crack your password if you still remember the form of your password.