Not all applications that you install create a menu entry. You'll have to manually add them yourself or start them from a terminal.
To find what packages are installed -- dpkg --list
To find files, programs, etc. type: man find or man which or use Konqueror to locate the program/s that you have installed and then add them to your menu by right-clicking on the dragon (or K icon) and selecting menu editor. You may want to search google on editing menus under KDE so you know the proper command to issue for starting the program, working directory if need be, etc..