Simply position the cursor and use the mouse wheel to zoom in/out at the desired location. You can compare this extension to pinch-to-zoom functionality on touch screens, or the Windows Magnifier.
Many touchpads support pinch-to-zoom in a way that they trigger the built-in page zoom. You can intercept this action if you change the zoom activation key from "RClick" to "Ctrl". This way, you don't need a mouse wheel to use Smooth Zoom!
