Best FREE apps/sites for PTCB prep?

Hello all!
I do not exactly have a lot of extra pocket money to pay for any of the official PTCB test prep exams, and I am sick & tired of making a username name & password for an app/website only to be directed to choose which monthly [paid] subscription I’d like to sign up for after registering. Are there any FREE apps, or links to websites that mimic the PTCB without being required to register & pay?

Thanks!