All users with access to the dialer can find the 10 last contacted leads.
It's possible to get a quick overview of the last 10 leads you've been in touch with. This can useful if you forget to write something important or save the lead with the wrong status, etc.
When you're located within the dialer, go to right side and click on this icon:
You'll get an overview of the 10 latest leads you've had open in the dialer. It is possible to open the lead in a new tab by clicking Open lead.