The Directory tool is very simple and small, but it can really come in handy - especially with the Batch Macros. All it does it read a list of files from a directory. In the past I had helped people do this with a RunCommand tool - which is less than elegant. I figure when I get asked about the same issue a half dozen times we should think about a feature, even if it is very mundane.
It has almost no configuration. It can really help with Dynamic Inputs or Batch Macros. Its output is a very detailed list of all the file information.
I was able to use it along with a Dynamic input and the reporting tools to count the lines of code in Alteryx (depending on what you count it is between 1M and 8M lines of code...).