I purchased the WordPress Download Manager Special Pack which has the directory addon listed, but I do not see it listed in the download. this is what I got.
crypton.zip
download-after-submit.zip
download-manager-4.5.6.zip
liveforms.zip
wpdm-advanced-custom-fields.zip
wpdm-amazon-s3.zip
wpdm-archive-page.zip
wpdm-block-hotlink.zip
wpdm-custom-access-level.zip
wpdm-daily-download.zip
wpdm-filemanager.zip
wpdm-ftp-file-browser.zip
wpdm-premium-packages.zip
