I have been looking for a way to have a grid-like alt-tab popup menu in contrast to the default, single row popup menu.
The only extension I have found that alters the popup menu is coverflow but not in the way I want.
I use Workspace Grid for managing workspaces and it has the grid-like layout that I am looking for from the application switcher.
Does this feature currently exist?
switchPopup.js and altTab.js should be the relevant for implementing this feature, and extensions Workspace Grid and Workspace Matrix, which I believe modify workspaceSwitcherPopup.js and workspace.js, should provide startup code.