giant.robot
Adventurer
GoodReader on iOS is great. You can manage files and folder inside the app, sync directly from cloud storage, and even upload through a web UI. It's a good PDF reader as well by not clouding the UI with a bunch of garbage.Can ask what your preferred way of reading PDFs is? I find myself moving in a similar direction. Currently mostly using iPad and Apple Books for syncing, but iCloud is on the pricey side, though I do like the bookshelf view and manual sorting of shelves