You can add any app, folder, or file to the Finder Toolbar:
Add a file or an app: Press and hold the Command key, then drag the item to the Finder toolbar until you see a green plus sign. Remove an item: Press and hold the Command key, then drag the item out of the toolbar. Rearrange the items in the toolbar: Press and hold the Command key, then drag an item to a new location.
I think it’s not about launching apps from Finder but dragging files into the apps to action on them. For instance, Preview will always launch when I double clicked on PDF docs in Finder. But what if I want to use PDF Expert to edit this particular pdf file? I drag it and drop onto PDF Expert icon in Finder.
I just learned this the other day too, what a cool feature. I don’t know how often I’m going to use it, but I love the way it looks to have Photoshop and Illustrator in that toolbar.
Anyone come up with any clever and intuitive uses for this?