What are the features of Invoices in Appointments organizer software ?

"In invoices section you can create invoice to your staff if required and to your customers by just a few clicks. Can implement GST required or not. Calculates the tax according to the selections and settings. Can send email of the the invoice to the respective person. Can view and print the invoice if required Your staff can also create invoices on the company behalf or on their individual names according to the company settings. Company can create invoice on behalf of the staff and send email. Generate reports of the invoices Able to mark as paid and unpaid invoices and filter them so tracking is easy. Can lock the invoices at any time. So once the invoices are locked it cannot be edited. Can create invoice and receipt simultaneously by just ticking one box Can create invoice in iphone and android apps also."