By connecting the app to an HC-05 Bluetooth board or similar, you can control a car made with motors, an Arduino Nano board, an L298 H-bridge, etc.
Movement is achieved by sliding your finger across the netbook mouse-like touchscreen.
This will allow the car to move smoothly without jerking.
Touch motion can also activate lights, the horn, and direct movement commands.
You can download the .ino source code to compile in the Arduino IDE and link the app to your car.
The program is configured for only two motors, meaning the car is either propelled or has a third wheel without traction.
The app requires a very low registration fee.