Very good, I liked the grouping. Things I found missing:
It would be much better if I could move the links up and down and determine their order by dragging them with the mouse. This should definitely be in later versions.
I wish I could manage the grouping order (if there is, I couldn't manage it)
After clicking Help, I had to use the browser's own back button. In my opinion, there should not be a help page, help can be shown as a popup on the bookmarks page and we can close it with the X button and see our links again... or you can add a button on the help page so that we can return to the bookmarks page.
We cannot change our username, so a simple profile page can be designed so that we can use this page for password change processes.
Also, in later versions, a field for statistics can be added next to the "Title" and "Created at" fields, how many times we clicked on the link we added, etc. In this way, in the future, you can use our statistics for promotion and make a statement such as: "Our users clicked on the bookmarks they added X times."
