Hey Ronald,
I've never warmed to Butler, although I've tested it several times over the years.
I use LaunchBar, and Keyboard Maestro cannot replace all its very useful functionality.
If for some reason LaunchBar disappeared tomorrow I'd switch to Alfred.
Keyboard Maestro is not equipped to do indexed searches for apps and other things like Butler, LaunchBar, and Alfred, although much of their functionality can be replicated in one way or another.
It is very simple to set up an abbreviation-based launcher:
Launch by Abbreviation v1.0.kmmacros (4.4 KB)
This macro retains the last abbreviation input.
It is also possible to create a smart-search dialog using the Custom HTML Prompt (see Dan Thomas' macro below).
MACRO: Spotlight Search Prompt
With that you can get pretty darn fancy, but you'll have to jump through some hoops to get it working.
-Chris