About 1.5 years ago, I tried out Ubuntu 11.04. I remember the dash being a rather helpful tool and I like the equivalent features on both Windows 7 (via the Start-button) and the Mac OS.

When I press Alt + F2, it opens the app finder but this only gives me a little window that I do not understand how to use. If I type in Terminal or Writer, it shows neither the command terminal or LibreOffice Writer.

How can I get functionality similar to the dash?

An important edit, because 14.04 happened

Synapse still works on 14.04! :) Please go here and upvote this post (click here).

Update 2019-09-13

I strongly suggest to use Albert: https://albertlauncher.github.io :)