Each drivers license practice test was made up of questions that had been on actual DMV permit exams, so I liked knowing that I was studying with the real thing. Plus, they had the same format as the DMV exam, so I got to take all the time I needed to familiarize myself and get comfortable with it.
Once you set up you practice test account you can log in and out of it as much as you want; your account is active for 6 months. There is no limit to how much studying you can do for your drivers permit test, but you’re also never forced to do anything you don’t want; it’s all about what you want and when you want it.
I know that these practice tests helped me pass my permit exam; I even saw some of the questions on my test!