If your workspace is overcrowded with small windows - use WorkspaceFree.
If you want to automaticaly hide/show some window - add it to the WorkspaceFree list by few mouse clicks. WorkspaceFree will remove from screen all present on the list windows . If you need any of them, move the mouse pointer to the edge of the screen where it is hidden and it will appear. WorkspaceFree allows you to add/remove windows to/from list, edit properties of each window, save/load configuration. You can minimize WorkspaceFree to System Tray.