The author says that doing something simple:

"takes several clicks on parts of the screen that are nowhere near each other and are not immediately obvious the first time you see them".

... and that this process requires the user to:

"click the “Ubuntu” button in the top left, then click the little white icon on the bottom center that is, I assume, representative of “a comb, a pencil and a building with pacman on it”. Then you expand the “Installed” section by clicking on the left/center of the screen. Then you click on “Filter Results” in the top right."

Doesn't like like a great thing to use at all to me.