To contribute to this great idea, I am looking at :-:
Use Case
A merchant installs your order-entry app, and the PayPal Here app, on a device. Then, a merchant can:
Use your app to assemble an order
Use your app to send the order, as an invoice, to launch the PayPal Here app
Use the PayPal Here app to adjust the amounts as necessary, or add items, and then accept payment with a credit card, PayPal, cash, an invoice or a check
Thus, during the Order and Payment Flow:
Your app sends an order to the PayPal Here app (using the API)
The order details are pre-populated within the PayPal Here app
The merchant uses the PayPal Here app to accept a payment
After the payment is successful, the merchant is returned to your app