...Admin can see list of all: appointments, providers, customers, and invoices. He can also issue invoices manually for all confirmed appointments. The provider can set his own working plan, add breaks to that working plan and change his available services. The provider sees only his own appointments. After the appointment status is changed to the finished system automatically sends an email to the customer with information that appointment is finished. In case the appointment didn't take place there is also a link attached to that email that allows customers to reject that the appointment didn't take place.