FlatSixDynamics vs DeckLearn

See real airflow around a reference car — free, no account, no subscription. One optional, one-time purchase (Full Access) unlocks the full speed range, additional views, every setup, and your own car from a photo. Bought the app before 2.0? You keep everything. FlatSixDynamics is a wind tunnel you can hold. The air around the silhouette of a rear-engined sports car moves live, frame by frame, right on your device. Change the setup, and watch the air answer. No footage. No fakery. Actual physics. You set it. You see the result. Drop the ride height from stock to track, and watch the floor start to work: the air under the car speeds up, pressure falls, and the body is pulled toward the road. Deploy the rear wing, and watch the wake behind the car close. Push the speed slider from a standstill to four hundred kilometers per hour, and watch the spoiler rise on its own, exactly as it does on the real vehicle. Every setup change comes back as a number. Track stance at two hundred kilometers per hour: watch the drag figure settle against stock, while the downforce reading breathes with the wake behind the car. Not your car's certified figures. But a number you can argue with. What's free The live airflow view on the reference car, stock stance, active spoiler, in a speed window of 50 to 90 km/h — wide enough to watch the spoiler deploy and the wake form. No time limit. What Full Access adds — The full speed range, up to four hundred kilometers per hour. — Pressure, cockpit, grid, and lab views. — The fixed-wing setup and the sport and track ride heights. — Your own car, traced from a side-profile photo. One-time purchase. No subscription. Restore purchases any time from Settings. What it shows — Stagnation at the nose, where the air piles up and pressure spikes. — Acceleration over the roof line, where pressure drops and the air runs fastest. — The gap under the floor, tightening as the car drops, and the pressure map answering. — Separation behind the rear glass, where the flow lets go of the body. — The wake. Swirling vortices. The quiet pressure recovery downstream. — The deployed rear spoiler bending the flow as the slider crosses ninety, then one hundred fifty kilometers per hour. Your own silhouette (Full Access) Bring a side-profile photo of a rear-engined sports car into the airflow view in place of the built-in reference shape. The outline is traced automatically, and the same live airflow — pressure, flow, wake — plays across your own car's form instead of the default one. Results depend on the vehicle and the angle of the photo. How it works A two-dimensional airflow model built on the full physics of compressible air — not a simplified approximation. Five hundred twelve by one hundred ninety-two cells. A body-fitted grid clusters resolution near the surface, where the boundary layer lives. The flow field shown as vector arrows. The pressure field shown as a heatmap. Nothing pre-rendered. Every frame is live. What it does not show A two-dimensional slice cannot capture the wing-tip vortices, the wheel wakes, the cooling air paths, the side-glass separation. Professional engineering teams work in three dimensions on industrial hardware. This is none of those things. If you came here for the aerodynamic intuition — the way a pressure wave hugs a roofline, the way the floor pulls harder as the car drops — the app will reward you. If you came here for numbers to put in a slide deck, please don't. Want to go deeper? (Full Access) Four guided explorations — a wing, a flowing shape, a narrowing channel, a track wing — reveal the same forces at work in their purest form. Optional. There when you're curious. What it runs on A modern iPhone. The airflow model is instrument-grade and runs entirely on-device. No server. No account. No tracking. Illustrative depiction. Real physics, two-dimensional, consumer hardware. Not for engineering use. No affiliation with any vehicle manufacturer.

Turn any spreadsheet into a flashcard deck, then study until every card sticks. DeckLearn imports a plain CSV file — a column of questions, a column of answers — and turns it into a deck you can quiz yourself on. No accounts, no subscription, no internet connection. Just your cards and your progress, on your phone. IMPORT IN SECONDS Pick a CSV and DeckLearn does the rest. It detects header rows automatically, handles quoted fields and commas inside answers, and shows you a live preview before anything is created. Files with extra columns work too — you choose which two become the front and back of each card. STUDY THE WAY THAT WORKS Three modes, switchable any time: • Shuffle — a fresh random order every pass • In Order — exactly the order from your file • Weakest First — the cards you keep missing come first New cards always come before ones you've seen, and the same card never appears twice in a row. MASTERY, NOT GUESSWORK Every card moves through New, Incorrect, Correct, Mastered. A card is mastered once you get it right several times in a row — three by default, adjustable per deck. Miss it, and the streak resets. Cards you've mastered leave the rotation so you spend your time on what you don't know yet. SPOT CHECKS KEEP IT HONEST Mastered cards get quietly mixed back in now and then to make sure they really stuck. Tune how often, or switch it off entirely. TWO-WAY CARDS Studying a language? Turn on reversible cards and DeckLearn will quiz you in both directions — term to definition and back again. Each direction tracks its own streak, and a card counts as mastered only when both are solid. Focus on one direction at a time whenever you want. SEE YOUR PROGRESS Every deck shows a live mastery ring and a colour-coded breakdown of where your cards stand. A statistics dashboard totals it all up across every deck — cards mastered, answers given, overall accuracy, and the running Energy count of every correct answer you've ever made. BUILT-IN SAFETY NET Graded a card wrong by accident? One tap takes it back. Reset a single card, or an entire deck, whenever you want a clean start. PRIVATE BY DESIGN DeckLearn has no accounts, no ads, no analytics, and no network access of any kind. Your decks never leave your iPhone. There is nothing to sign up for and nothing to opt out of. Requires iPhone running iOS 17 or later.