Arcmark

Arcmark is a native macOS application that attaches to browser windows as a floating sidebar for quick bookmark access. It supports Chrome, Arc, Safari, Brave, and other browsers, letting users organize bookmarks into custom-colored workspaces with nested folder hierarchies. The maker describes it as inspired by Arc Browser's sidebar organization system.

Features include drag-and-drop reordering, inline editing, search across workspaces, automatic favicon fetching, and import from Chrome, Safari, Firefox, or Arc. All data is stored locally in a single JSON file with no cloud sync or accounts required. The project was built using Swift and AppKit, and is free and open source under the MIT license.