WindowClipMBI is a an app that you use to create pictures of any window in any app easily from the menu bar. You can also create timed "composite" pictures of all the current windows of an app, including items like menus and help tags. You can grab timed screen shots that optionally include the current mouse cursor image.
Use the Preferences window to select various options. You can opt to not include windows framing effects like shadows, or choose that the image is opaque rather than transparent. You can also select an option to include the Desktop picture in composite shots, and specify the delay when taking a composite shot so that you can set up the windows, such as by making menu selections or displaying help tags so they are captured also.
When you select an app menu item the image of that window is put on the clipboard, and optionally opened in Preview. You can apply special effects, using Core Image filters, to the images - such as making the image monochrome.