This app lets you changes the Android disk encryption password. You will only be required to use the new password at the next boot, so it is important not to forget it until then, and take a full backup just in case. Short of brute-forcing, the only way to recover from a forgotten encryption password is to factory reset the device, deleting all user data in the process, so proceed with caution. The app will verify that you have root access by checking if you have one of the more popular 'superuser' apps (Superuser or SuperSU) installed, and trying to execute a dummy command with su at startup. If your device is not encrypted, it will refuse to start.