Sonus - Vroom

Sonus turns the push you feel into the engine you wish you had.

The phone's accelerometer samples acceleration 100 times a second. Sonus turns that into virtual revs, gears and load, then builds the sound from eight looping layers per engine — crossfaded and varispeed-shifted so the pitch tracks the revs the way a real engine does. Nothing is pre-rendered, so no two drives sound the same.

WHAT YOU GET

• Seven engines — V8, V12, turbocharged inline-six, four-cylinder, flat-six, electric motor and a V-twin. Each with its own idle, redline and gearbox.
• Lift-off backfire and upshift thud on the engines that have them.
• A trip log: peak G, top speed and 0–100 for every drive.
• Dynamic Island and Lock Screen: revs, gear and G while you drive.
• An Apple Watch companion — start and stop from your wrist, with a rev ring.
• A manual mode that drives the whole chain with four buttons, no car needed.

HOW IT SOUNDS RIGHT

• GPS corrects the speed estimate, because an accelerometer cannot see a steady cruise. Lose the fix in a tunnel and the estimate holds instead of dropping to idle.
• A calibration pull teaches Sonus where the car's nose is, so a phone mounted sideways or at an angle still reads acceleration correctly.
• Latency compensation runs the engine slightly early, so a Bluetooth speaker lands the sound with the push instead of after it.
• The mix runs through a limiter, so it is loud without clipping, and it shares the stereo with music and navigation.

SAFETY AND PRIVACY

Sonus only makes sound. It never connects to the car and changes nothing about how the car behaves. Hold IGNITION for half a second to start, so a brushed phone does not start it for you.

Everything runs on the device. No account, no analytics, no data leaves the phone. Location is used only while the sound is running.

ONE PURCHASE

Sonus is free with one engine. A single in-app purchase unlocks all seven, for good — no subscription, no ads, no consumables.

Every engine sound is synthesised, not a recording of a real car; the names are original and represent no real vehicle.