The Etsy Sales App is a great way to receive notifications of sales as and when they come in. Even if you are integrating products with an outside manufacturer, it is useful to monitor the orders - to see special requests the customer might make for example.
You can also monitor sales and times when customers favourite items.
In addition, you can change the status of orders - notifying customers that their orders have been despatched once you've posted them off.
The App is free, and I recommend Etsy store owners add it to their phones and/or tablets.