PicPick Portable v4.2.0
I think there is a bug in the way PicPick Portable has been made into a PortableApp. As far as I am aware a properly constructed PortableApp should not be writing anywhere but in the PortableApp's own directory structure on the flash drive. However, on launching PicPick Portable it creates a folder at the following path:
C:\Users\UserName\AppData\Roaming\PicPick
If this is a bug it needs fixed.
Hope this helps.