Answers
When I upload a family file to my phone it leaves behind a corresponding .touchcard file in my ~/Documents/ folder.
The .touchcard file is created by Reunion for Macintosh when you send your family file to the iPhone. It's supposed to be deleted when the transfer is complete. It appears that it's not getting deleted (at least not in all cases) so this is a bug we will fix.
These files are of no value and should be deleted.