It would be great to have an ability to customize invoices, create different templates and have separate numeration systems for them. It would help to adapt invoices to our local regulation.
Also I really miss the possibility to create invoices in few languages (changing language with one click) as we deal with customers from different countries.
Add possibility to assign circles for Work Request items and Appointment types. We deal with few groups of customers (subscribes, non subscribes etc) and it would be easier and more clear for them if they see only those items or appt types which are intended for a certain group/circle.