Easy Layer Manager is a Blender add-on from Easy Team that adds a viewport-based layer system, replacing the Outliner workflow. Layer control lives in a draggable HUD, so you can organize a scene without opening the Outliner.
From the HUD you can create layers instantly, reorder them with drag-and-drop, and use a search bar to filter layers or objects. Multi-selection with Shift and Ctrl lets you batch-toggle visibility, render visibility, selection, and lock. Assign selected objects to the active layer with one click, expand layers to manage the objects inside, and merge selected layers into one with automatic object merging. Selecting a layer or object highlights it in the Outliner, and a view mode switcher moves between Shaded, Wireframe Shaded, Wireframe, and Bounding Box.
Version 1.1 adds a resizable HUD, an Isolate Layer option via Alt+click on the visibility eye, and HiDPI/Retina scaling with Auto, Standard, and Retina display modes. It is compatible with Blender 4.5 and later and is released under the GPL license.