Motion controls: tilt the phone to steer
Your phone already has the same motion sensors a fancy controller uses for gyro aim. QR Controller just points them at a steering axis. Hold the phone sideways like a wheel, tap Enable Motion Control, and tilting left and right steers the car.
Here's what it actually looks like in motion.
It feels surprisingly natural. People who have never touched the app are drifting around within about a minute. No stick to learn, you just tilt the phone.

You can set how far you have to tilt for full lock, so a twitchy arcade racer and a heavier sim can both feel right. Wheels aren't the only use either, any axis can be driven by tilt in your own layouts.
Want to try it?QR Controller is on Steam with tilt steering built into the racing layouts. Friends scan a QR code and they're steering with their phones.