Window-list – Application indicator to display a list of all current open windows
window-list is an application indicator to display a list of all current open windows. Each window can be activated by selecting from from the list.
Install window-list in ubuntu
Open the terminal and run the following commands
sudo add-apt-repository ppa:jwigley/window-list
sudo apt-get update
sudo apt-get install window-list
Screenshot
Via Askubuntu