Pass your CDL knowledge test — and understand why.
Most CDL apps tell you an answer is wrong. This one tells you why, and shows you the exact section of the official manual it came from.
Every question is explained and cited.
1,519 practice questions across all eight CDL topics, including questions written from your own state's manual where its rules differ. Each one carries a written explanation and a citation to the official Commercial Driver License Manual — tap it and read the source passage yourself. No question is here on our say-so. Still not clear? Explain differently rewords the explanation in plainer language, and is never allowed to add a fact or a number.
Your state's official manual, offline.
The complete CDL manual for all 51 US jurisdictions is built into the app. No signal needed — useful at a truck stop, in a yard, or in a sleeper berth.
An AI tutor that won't make things up.
Ask anything about commercial driving. Answers come only from the official manual text, always cite the section, and when the manual doesn't cover something it says so instead of guessing. Manual search works with no connection at all.
Listen to the manual.
Have your state's manual read aloud, section by section, with each sentence highlighted as it is spoken — or run a hands-free review that reads a question, pauses for your answer, then gives the right one and the manual's own words. Built-in voices, works offline, and keeps playing with your phone locked, with play, pause and skip on the lock screen.
Study what you're actually weak at.
Spaced repetition brings back the questions you get wrong, at the moment you're about to forget them. Set your test date and the schedule compresses to fit. And every question you've missed is grouped by the section of the manual it came from, so you know exactly what to re-read — and can drill just those.
Exams that match the real thing.
Timed mock exams at the real question counts, scored against the federal 80% pass mark. Review every question you missed afterwards, in the exact order you saw it.
Practise the skills test.
Five trainers, in the order the examiner runs the test: the pre-trip inspection, the air brake check, coupling and uncoupling, the basic control skills (the backing exercises and how they are scored) and the road test, school bus student discharge included. Each lays out your state's manual, word for word, for the vehicle you'll test in — tractor-trailer, straight truck, school bus or coach — and drills it: say the checks out loud, put the steps in order, sort each road-test step under the moment it belongs to, and fill in the figures your manual prints. (Where a manual does not print a procedure, the app says so, or shows you where it is — it never borrows another state's.)
Covers every endorsement:
General Knowledge · Air Brakes · Combination Vehicles · Hazardous Materials · Passenger · Tanker · School Bus · Doubles/Triples
No ads. No account. Every practice question, the full manual, manual search, mock exams, your study plan and the skills test checklists work without paying.
Subscription.
An optional weekly subscription unlocks the AI tutor beyond three free messages (up to 20 a day) along with Explain differently, Listen, the missed-questions review and the skills test drills. New subscribers start with a 7-day free trial, and your Apple Account is charged when it ends unless you cancel at least 24 hours before. Otherwise payment is charged when you confirm the purchase. The subscription renews automatically unless it is cancelled at least 24 hours before the end of the current period, and can be managed or cancelled in your Apple Account settings.
Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Privacy Policy: https://twistedsociety.github.io/cdl-pp.html
Readiness scores are a study aid, not a prediction. Always check your own state's current requirements with your DMV — rules and fees change.
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