Will scan your Workbooks and TDS files, searching out, extracting, and recording the Custom SQL they contain.
It's available on GitHub here.
It's Tableau Tools wiki page is here, providing the basic information about it.
There's not much in the way of visuals to show for this tool. The Tableau Sample Workbooks don't use Custom SQL, and most of the Custom SQL in my usual Tableau archive isn't something that can be released into the wild.