Bring Task Manager window using Ctrl-Esc key combination or double click on free desktop area. Select required application window from the list and press Switch To button on double click on window name in list.
Bring Task Manager window, select application window in list and press End Task button.
Bring Task Manager window and press Cascade to position window as cascade from left top corner of desktop. To tile windows vertically press Tile button. To tile windows horizontally press Tile button with Shift key pressed down.
Bring Task Manager window and press Arrange Icons to arrainge icons on desktop.
Press Esc key, Cancel button or use Close item of System menu.
You can download source code and binaries from GitHub. Task Manager comes under osFree license.