Custom field in customer#3567

We intend to use the plugin as a booking system for dog grooming. I bought the pro version and would like to be able to add custom fields to the customer adding screen.

In my case I want to be able to add dog name(s), breed(s) and special notes for the customers dogs.

Currently I was able to add the custom fields to the Appointment addition screen, but it would be better for us if at the time of scheduling an appointment we could select the dog or dogs that customer has including their name, breed and special notes.

We do not plan to use this plugin to allow our clients to make their own appointments, appointments will be scheduled internally.