Alfred has had competition, but it remains my launcher of choice.
Out of its many features, one stands out as a huge boost to my productivity and comfort using computers: the clipboard history.
I've tried clipboard history apps on Windows and Linux, but Alfred's design is miles ahead.
It keeps up to months of history.
It automatically ignores entries from password management apps.
One global shortcut to search.
One keypress to insert.
While for me, tiling window managers are the “killer app” for Linux, Alfred is the “killer app” for Mac.