Serve the customer, not the software
A queue doesn't wait while you fill a form. Scan, total, take the money, print — and the stock, the ledger and the day's profit all update themselves behind the scene.
No customer name required to ring a sale. Attach one only when it matters — a repair, a warranty, or credit.
Plug in a USB barcode scanner and it types for you. No scanner at the second counter? Use the phone camera instead.
Cash, card, JazzCash, EasyPaisa — or put it on the customer's udhaar and it posts straight to their ledger.