if you only want to use the .app file as an usual application, just drop it into your "Applications" folder and run it.
I recommend dropping it into the Dock so you can just click on it instead of searching it via Spotlight :)
IMPORTANT: The app will assume that the Cache-Files of your Final Cut Pro Libraries are saved into your "Movies" Folder!
So make sure the settings of your library are set accordingly. Of course you can change the Path inside the ".scpt"-File to whatever you want.
maybe I'll publish an update that solves this problem later :)
Just open the .app file and a Dialog will appear. If there are no Cache-Files ("fcpcache" Extension) it will tell you, press "Enter" or Click "OK"
If there were Cache-Files ("fcpcache" Extension) found, it will tell you Amount and total Size of these and give you the option to delete them. After that it asks to empty the trash.
To speed up the process, you can just always hit "Enter" every time a Dialog appears.
of course you can always cancel the Dialog. Klicking "Cancel" will also quit the Application
I hope my little Application helps you keeping space on your Disks :)