This is a Mozilla Firefox extension that allows you to quickly replace an existing bookmark with a bookmark of current page.

Can be useful for reading and tracking progress in series of articles, webcomics, serial online fiction, etc.

When you click on the icon (or use the hotkey), it builds a list of bookmarks from the same domain as the current URL, sorts them by similarity, and gives you a prompt to choose. The new bookmark retains the folder, position, all tags and all keywords of the old one.

If you check "Keep the old title", the previous title will also be carried over to the new bookmark.

Icon by Yusuke Kamiyamane.