[xmonad] knowing what is on each workspace and/or knowing which workspace I am looking at

Dear all, I never managed to have a way of knowing either 1- on which workspace a particular program is open or 2- which workspace is being displayed on each of my monitors (eg, "on this monitor you are looking at workspace 1") Is there a way to get either of these behaviors? Without this information, I do spend some serious time zapping across workspaces to find the window I need. I thought that an easy way to address (2) would be to use an OSD (like libnotify) to pop up a notification providing the workspace name/number when the user switches workspaces. Is there a "hook" in xmonad to which I could link a command "run notification saying this is workspace X"? Many thanks for any help ~lara