Bookmark managers with duplicate resolver
Bookmark OS is like Mac and Windows for bookmarks. It gives an intuitive and powerful interface for organizing your bookmarks.
Deskyo lets you save, import, classify, manage, access and find your bookmarks very quickly. It is meant to look like your desktop and has icons and folders.
Raindrop.io is a bookmark manager that behaves as a single page app. It allows you to drag and drop, change icons, and sort your bookmarks.
Starpage is a traditional and fully featured start page with widgets. You can organize bookmarks along with widgets such as weather and news.
Bookmark Ninja has a start page type layout and allows you to add categories, drag and drop, and use different column layouts.
Zotero bills itself as your personal research assistant. It allows you to add citations and organize bookmarks in a list-based style.
BookMacster is a downloadable app that has features such as tagging, sorting, and getting rid of duplicates.
URL Manager Pro is a bookmark manager that resembles a file manager.