Click on a colour and size, then click on the circle in the drawing area and move your mouse around to draw! Press spacebar to release the circle and stop drawing, you can also drag the circle to the desired position after releasing it to start drawing from there. The white box next to the colours shows the colour that you have currently selected. On phone, click on the release button to release the circle and click on it to start drawing.
Just draw and enjoy! Mobile Friendly!