With the redial button in Callbar you can quickly reach out to the last dialed number.
You will see this button next to the input field above the dialer pad.
If you click on the button, it will populate the input field with the last dialed number.
When the number shows up, you just need to press Enter or click the green Call button to make the call. This way, you can make sure that you are redialing the right number.