If you forgot your PLIC Apps password, don't fret. Simply use the [Forgot Password] link on the sign in page for whichever PLIC application you want (PLIC Books, PLIC Go!, PLIC Elements, etc.). Since they are all connected, you will change for all with one fail swoop.
Just input your Email address you used for your account and you will receive an email to reset your password.
Don't forget to write your new password down.