Consider window titles on search result

Now that the dock it's disable by default, this feature could help for fast browsing to different instances of the same program, like Filer or maybe also browser tabs?

What you are essentially asking for is that the Windows menu (on the right-hand side of the screen) should also be searchable...

I don't know whether that's feasible given that it's living in its own plugin, but maybe @jsm222 knows?