By default, when you reveal a file it will be shown in Finder. If you want to, you can use another application to reveal files. You can do so by setting the customFileRevealApplication key in the GrandPerspective user defaults to the name of the application that you want to use instead. This can be done in the Terminal by entering the following: defaults write net.sourceforge.grandperspectiv customFileRevealApplication -string ApplicationName. Please make sure that GrandPerspective is not running when you do this, otherwise there is a chance that the change will be undone by the application.