I always had this in mind for the just-retired Mini Bridge, but we never quite got there. PetaPixel writes,
Doco’s goal is to help you better view and manage multiple Photoshop documents when they’re open at the same time. Using the extension’s cleverly-designed panel, swapping between images or compositions becomes a far more intuitive experience… no more having to remember what tab holds what photo.
The panel site says,
Doco brilliantly lets you copy selected layers or adjustments from document to document with a simple drag and drop. Moreover, drop the layers icon outside and Doco will create a new document for you. How awesome is that!