This is our own one-of-a-kind feature. Start Menu X replaces the yellow folder icons with application icons. Clicking on the folder launches the application. To access a submenu, hover the cursor over a folder for a few seconds. For the first launch, the application launched is determined automatically. Subsequently, the application that you most recently launched becomes the folder's "default application".
This feature makes use of your visual memory, significantly accelerating your ability to find and launch applications.