The Redial feature keeps track of the last 10 unique phone numbers you dialed from with Handy. These phone numbers will be available for quick access from any dialing related menu.
You can dial any number in your redial list from any of the Dialing related menu commands. These include the Actions/Dial Phone/Redial menu from the main window, the Redial menu from the system tray, or the Dial Phone/Redial menu that appears when you right mouse click in the main window.