Duplicate Windows lets you select from among all window objects known to the operating system.
Once you have selected a window, the new copy changes its size to match the window you have asked it to duplicate.
When you resize the new window, the Duplicate Windows app will maintain the aspect ratio of the source window. The new copy keeps itself up-to-date fast enough to keep up with just about anything, from video to fast animation. Mouse clicks and key presses on the copy are not forwarded to the original, and so far the program does not work across spaces.
Duplicate Windows is capable of copying a window that is actively playing a video, though not without some slight artifacts.
Duplicate Windows fails to render windows that are across Spaces, or windows that are minimized. The list of windows available to duplicate includes the menu bar, all the UI services icons (the small icons on the right side of the Menu Bar), and many other things you may not have known were windows. This is a little confusing at first, but technically necessary to provide maximal flexibility to the tool.
NOTE: To buy Duplicate Windows via the App Store, an Apple account is required.
Here are some key features of "Duplicate Windows":
· Full screen duplication
· Floating windows or standard level windows
· Borderless windows
· Duplicate multiple windows
· Resizable duplicate windows
· Multiple monitor support