A long time ago there was a utility called Katapult, a great application launcher for KDE. I liked the auto completion of application name or website address as I typed in the letter on my keyboard. Katapult is now deprecated, no longer installed with KDE.
But there is another great application launcher for KDE, called Krunner. The shortcut is ALT+F2, and the functionality is mostly the same. I don’t miss Katapult anymore.