From AppleScripts by Tom X:
iShow Invisible shows and hides the invisible files using a repeating dialog box. After you have revealed the invisible files, simply move the Hide dialog box out of your way or press Command-H to send it to the background. Any open folders should remain open when you change the visibility. This makes it easier if you have several folders open and want to view the invisible files.
None. Do not use this application to tamper with the invisible files. Leave them alone!
You may end up, (like me playing with "iShow Invisible"), with a corrupt disk where some files and folders are left invisible although they should be visible. I was sensible enough to have a fresh backup!
Do not touch this application, since it is extremely unreliable and dangerous to use!