I was also a long-time user of Papaly, and it was really frustrating when it stopped working. After trying several alternatives, I finally found one that works really well for me: Speed Dial | Bookmarks Manager for New Tab Page (addon.logreel.xyz). It has a clean interface, syncs well, and offers a similar bookmarking experience to what Papaly had. Hope this helps anyone still looking for a good replacement!
I used papaly for such a long time and it's a great bookmarking platform. If it had the ability to view the layout in cards and more customization options in general I would still use it but it is still top 5 i've ever used.
Pros:Organized, Easy to use, Subcategories, Everything of a category is one dashboard for easy searching, RSS feed bookmarking, completely free
Cons:One layout option, no subcategories of main pages, no tagging feature, no favouriting feature