App Sales Machine also scrapes your app's rankings, so that config file is used to generate the URLs to scrape. From there, I relied on it to help organise the way the data is persisted in the data store. I suppose it could be modified to parse everything it needed from the sales reports, but you would still need to configure every app's category info for the rankings scraper. I'm sure there are other ways of doing it, but this is the method I settled on.