One great part about the WAB Public Notification App is the ability to add the Print Widget. Whenever we do a list for public notification, we always have to send a picture of the area related to the mailing list. To me, these go hand in hand, so it'd be the bee knees to be able to download a printable map with the features selected, to accompany the PDF or CSV. I know this is an "instant app", but I could easily see a button after the CSV option in the side panel for printing.
The perk of the instant app over the WAB is the ability to "remove duplicates"! Just add in the download/print function and it's a complete package!