MotionCalm: Car Sickness Aid

Use your phone in a moving vehicle without the nausea.

Motion sickness starts when your inner ear reports movement your eyes cannot see. Look down at a screen in a car, bus, train or boat and that mismatch is at its worst. MotionCalm closes it: a quiet cue at the edges of your screen drifts against the vehicle's motion, giving your eyes the movement your body already feels.

It runs on top of everything else. Read, watch a film, play a game, reply to messages — the cue stays at the edges and never takes a tap.

Two styles, both flat

• Dots. Small dots around all four edges of the screen, drifting against the motion. More of them, larger, travelling further as the movement grows.
• Edge glow. One soft line following your phone's own bezel, with the edge you are pushed toward lighting up and sliding as the vehicle brakes, accelerates or corners.

Both are a flat, two-dimensional drift. Nothing zooms, nothing looms, nothing simulates depth — the cue reports the direction of travel and nothing else.

How it behaves

• Quiet when still. At rest the cue is barely there — a sparse ring of dots, or a line that sits at a tenth of its brightness.
• Reacts to real motion. Brake, corner or pull away and the cue answers within a tenth of a second, then settles as the movement stops.
• Reads two sensors, not one. The accelerometer measures the vehicle; the gyroscope measures the phone. That pairing is why tilting the phone in your hands does not produce a false cue, and why a long steady bend keeps showing motion instead of fading out halfway round.
• Right way round at any angle. The cue is worked out in a frame referenced to gravity and to the display's rotation, so it means the same thing whether the phone is flat on your lap, held upright, or turned to landscape.
• Passes touches through. The cue never intercepts input.

Make it yours

• Pick dots or the edge glow.
• Dots: larger, more of them, and a fixed or a reactive pattern.
• Edge glow: how far the line sits from the bezel, from flush against it inward.
• Strong effect for gentler motion — smooth roads, or a train.
• Seven colours, or Auto, which follows your light and dark theme.
• A Quick Settings tile, so the cue goes on as the journey starts without opening the app.

Battery

• Idle until you travel. In Auto mode nothing is measured until a journey is detected.
• Stops with your screen. Both sensors are released the moment the display goes dark.
• Redraws only on change. A phone at rest costs nothing.

Privacy

• No location. GPS is never requested or read.
• No accounts, no ads, no advertising ID, no tracking across apps.
• Sensor readings never leave your phone. They are used for the current frame and discarded.
• What is sent: two anonymous counters — the cue being switched on or off, and which run mode you chose — plus a crash report if the app fails. That is the complete list, and the privacy policy spells it out.

Good to know

Turn the cue on before you start using your phone — read, play, watch or message on the move. It works as prevention, not as a cure once you already feel unwell. On a train, bus or boat, pick Always on — automatic detection leans on signals that mostly come from cars, so Auto can stay quiet on other transport. Use it as a passenger, not while driving. MotionCalm is not a medical device and does not diagnose or treat any condition. Talk to a doctor about severe or persistent motion sickness.