CDL Prep is the best way to prepare for the Commercial Drivers License General Knowledge, and various endorsement exams. CDL Prep contains questions on the following topics: General Commercial, Air Brakes, Combinations, Hazmat, Passenger, Tanks, School Bus, and Doubles/Triples.

1. Over 500 questions to practice with.

2. Exam Mode - 60 minutes to answer 50 randomly chosen questions, or 40 minutes to answer 20 to 30 questions on endorsement topics. At the end, review your score and any incorrect answers.

3. Practice Mode - Answer questions and receive instant feedback if you answered incorrectly.

4. Answer Randomization - Answers to questions will not always be in the same position.

Please send any feedback or request to: Thank you for reading, and good luck on your exams!

What’s New

Version 7.5

Corrected grammatical mistakes and fixed a bug which caused crashes for some users.

Ratings and Reviews

4.7 out of 5
1.1K Ratings

1.1K Ratings

Communist_Jesus ,

I was skeptical

Arrived in Missouri for trucking like I’m sure many of you are reading this. Had instructors trash talk this app saying it wasn’t accurate, but lo and behold, I passed with 90% or greater on all four endorsement tests. It works. Make this your Bible and study it until you want to vomit, then study again and you will pass. My only complaint is that there were some questions on the general knowledge portion that were not on this app, but I still managed to pass it with 90% and so should you. The other endorsements were 100% accurate compared to this prep app. Hats off to the app creator, thank you sir. Also, you can skip ads even if there isn’t an X mark in the top right corner by just tapping on it, the ads help make it free for the developer to profit and honestly weren’t too annoying once I figured out how to skip immediately. Good luck!

Developer Response ,

I will review and correct if necessary, thanks for the report.

SpeedwayCP ,

Super helpful study tool

This app is a great studying resource when prepping to take your CDL permit test. Before downloading it I looked at the reviews and one said to study it like it’s your bible! And that’s so true!! I read through the manual before finding this app, but I think that this allowed me to recall and really understand what I read. It’s awesome how it has a “see why” option when you miss a question. This allows you to look back at your manual and read about it. I took my general knowledge, combination and air brake tests out of Indiana. The GK test is about 90% similar to the questions they have on here. I passed and only missed a few on my first try. For the combination test, it’s about 95% similar to the questions on here. I passed on first try. I still have yet to take the air brakes but I will update after.

iTsKael ,

Go no further!

Hands down this app was one of the best tools to study for the written test! I decided to get this app because I talked to a few people and they said that this test was fairly difficult and that it took some 2 times to pass. I strongly recommend reading the book first so to better understand everything you need to know because let’s face it this app is what it is a means to test your knowledge. After I went through the book and felt comfortable then I took the test. The nice thing too about the app test questions is that they are verbatim on the state test BUT they wording may be different to trick you so PAY attention and don’t assume you know the answer without reading the full question. Anyways, I passed the test first try and strongly recommend this App to help you prepare. Good luck!


Jeffrey Diaz
15.2 MB

Requires iOS 12.1 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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