Sticky Previews v1.7

Sticky Previews can create live previews of any window or a screen region of your choice.

It keeps previews above all other applications like a sticky-note thus allowing you to monitor any background window in real time.

For example, you can use this to watch YouTube videos running in the background while you do something else. In a way, it almost allows you to turn any portion of any windows into a widget so you don't miss anything, and don't have to manually change window to see stock quotes, football scores or whatever it may be.