Capture Active Window Client

   Click "Capture > Active Window Client" menu item to capture "topmost" window, but do not capture its window frame, just the portion of the window inside of the frame. Great for grabbing the contents of a window without such things as toolbars, menus, and so forth. You can also set the Default / Last capture to Active Window Client under the Capture tab of Capture settings dialog, then press the hotkey or click "Capture > Default / Last capture" menu item to start capture.
When capturing, Quick Screenshot Maker will hides itself. To view Quick Screenshot Maker after capture, check the "Show main window" option under the Edit tab of Capture settings dialog, if not, Quick Screenshot Maker will be minimized (visible only on the system tray area) and you'll have to click on it to open it up again.

   If you want to include cursor, check the Include cursor image option under the Capture tab of Capture settings dialog.

   The program will finish capture active window client immediately after you start capture. You can see the captured image in the viewer.