I typically use Dropbox and Pinterest for similar purposes, but I thought I'd give this app a try for organizing boards that are hopefully easier to access for others. My partner and I are moving in together, and I'm using a dedicated board to post inspiration and links to products.
While I've only viewed it logged in on my phone so far, it seems promising.
Unfortunately, I'm having trouble with one basic, major feature: deleting items. Even though I click to delete and then confirm when prompted, items do not delete from boards + single item views. My workaround is to "move" these items instead to a "trash" board which actually removes them from the other board/views. Pretty weird flaw, though. I even updated a bit ago to see if it squashed this bug, but no luck.
UX-wise, it would also make more sense to have the "boards" tab be the first, default screen before the "all items" one at the bottom of the interface. Since the primary functionality revolves around themed collections of info, there's little use in seeing content from all boards smooshed together when launched.
Otherwise, cool idea, and I have loved WeTransfer on its own for ages, so we'll see how it goes!