The FooSales app only allows you to complete an order as cash or card at the moment. This means that you would need to manually process payments using a third-party card machine. You would then simply tap the card button and FooSales will add metadata to the order so that you can see what the payment method was in your WooCommerce back-end. The benefit of this is that FooSales does not limit you to a specific service provider and you can therefore use any service that suits your needs in terms of cost and availability.
FooSales doesn’t currently integrate directly with third-party card machines or online payment gateways.