Improve EPOS

We run a small shop front counter in our unit and use the EPOS function every day. However as SF know its a very very very basic stripped down of a POS system. I feel this could be updated even to give a simple functions like change to give to customer, as sometimes using a calculator can be a tad imbarrising. Or any kind integration with any POS system out there so we can buy and link that to our system.