This is an extension that adds number badges to tabs when you press CTRL-ALT. With the extension installed you will be able to add number badges to the title of tabs as such:

# - original_title

This will make it easy for you to identify the index of the tab you would like to navigate to using the shortcut key combination, such as CMD-# on MAC and CTRL-# on WINDOWS.

Note: This extension only works on tabs that have a web page loaded. If you wish to use this extension you will need to install it first.