Plasma/Krunner
Krunner
Krunner as a calculator
You can use Krunner as an efficient calculator. It's very easy to use too. Just press Alt+F2 and type the expression you want to evaluate such as 32*12= or =32*12 (You can put the = sign before or after the expression).
It is possible to evaluate more sophisticated expressions such as:
=sqrt(4) + 32 * sin(60)
Using it as an application launcher
This you probably already knew, Krunner can also launch applications. Start Krunner (Alt+F2) and type the name of the application you want to run.
Running BASH commands
The good thing about Krunner is that it doesn't only recognize applications, but it recognizes all binaries throughout your system. You can use this ability to run bash commands such as cp, mv, etc.
To do so, start Krunner (Alt+F2) and type the commands just as you would in Konsole:
cp ~/Documents/myFile ~/myFile (not a useful example but you get the idea)
Say you searched for an item in runner that brought you more than one result. And say you don't want to move your hand to reach the mouse to select the item. How would you go about it?
You can use the 'Tab' key on your keyboard to navigate through the results!! Then just press Enter to select/run the item!