I would also love to have/make an app which tells you what river you're beside and how that eventually flows into the sea/ocean. It's a type of distance that's not as the crow flies, but as the river flows.
@yomimono Oh awesome! And that site works for me now BTW
@ebel This reminded me of an excellent (unfortunately US-only) visualization of watersheds I saw presented at a conference once: https://github.com/embeepea/watersheds , it shows upstream in red and downstream in blue for arbitrary points. It looks like it might still be live at http://watersheds.fernleafinteractive.com/ , but it sits at "loading..." for a long time for me :(