I read through the operators manual, took the pretest at the end of the manual, then found this app, and took the quizzes a couple dozen times. Afterwards, I took my real permit test and breezed through it. The DMV clerk said that was the fastest he ever saw someone go through it.
The questions are identical to the pretest in the owners manual and the permit exam itself. The app is definitely more convenient than working off a pdf, plus contains some helpful links as to the next steps of the licensing process.
My only recommendation would be to provide an option to take you through all 80-something questions in the operations pretest. I was seeing the same questions over and over, but was still getting an occasional question that hadn’t yet appeared after more than a dozen attempts. Someone may take the quiz twice and think they are completely prepared, then run into a permit test version which contains none of the questions they saw in the app. All that said, this app was a tremendous help. I started prepping on Wednesday, and passed my permit with a perfect score the very next day.