Copyright Now reads the photo folders on your computer and works out how many separate copyright applications your archive needs, which type each one is, and what the Copyright Office will charge. Then it builds the paperwork.
Phones do not give a browser access to those folders, so this part runs on a desktop.
Send yourself the link and pick it up there.
Pick any folder of photos. Add more whenever you want.
Nothing is uploaded. The scan runs in this browser tab, on your computer.