Most of us have at least once in life faced a situation where we wanted to work on a selected window while having another one on top of it. A perfect example would be the want of watching a movie or a video while working on some other process. Other cases could involve referring to a document that is the base of your work for another.
Out of many tools supporting this feature, I selected On Top Replica as the one that I wanted to cover.
On Top Replica is a light weight Windows application that lets you clone a window and keep it always on top. You may create a thumbnail preview of a certain window and keep it visible, no matter what Window you are working on.