I don't know the app, but I wouldn't use a third party utility for that (although my guess is that it's just a front end GUI for these Terminal commands):
To show all hidden:
Launch Terminal and copy and paste this command:
defaults write com.apple.finder AppleShowAllFiles YES
To hide them again:
defaults write com.apple.finder AppleShowAllFiles NO
For individual files:
To Hide
To make a file/folder hidden you can do the following.
open Terminal.app (it's in /Applications/Utilities) and type
sudo chflags hidden
Then drag the file or folder you want hidden to your Terminal window.
It will now show the path to the item.
Press Return.
To Unhide:
Type
sudo chflags nohidden
Then drag the file or folder you want unhidden to your Terminal window.
It will now show the path to the item.
Press Return.
Universally unhide ~/Library on all volumes
chflags nohidden /Volumes/*/Users/*/Library
chflags nohidden /Users/name
To unhide the ~/Library
chflags nohidden ~/Library