For all stores with traditional checkout-counters, the best variant is to run GreenBill on a separate display/ interface. This display can be played anywhere at the POS in reach of the customer to interact with it.
In the case of checkout systems that do not have an integrated customer display, this offers the additional advantage that the customer can easily and conveniently check the amount and scope of his order.
Customers are not required to have an app installed on their phones or to pre-register.
Instead, every receipt can easily be opened via QR-Code scan in your browser and be shared or downloaded.
Another option is to allow users to send the receipt via email to themselves or their accounting.
Every receipt can be displayed on an interface. For this, either a tablet or smartphone can be used. All cashier systems that don't have a built-in customer display benefit from this especially, as now the customer can check the receipt before paying.
This is how your customer interface will look like: