Bar Patrol allows you to place your orders and create invoices in one click (two clicks total), either on the online dashboard or inside the app. In order to set this up, you need to set your par levels and re-order points for each product. Once that is done, you are able to run a purchase order based off of your latest inventory count and the purchase order will tell you exactly how much to order of each product to get back to par. At this point, you simply submit the order and it is emailed off to your suppliers.
For invoicing, once the order comes in, you simply make sure everything is accounted for, then using the app or online dashboard, find your purchase order and hit Approve Invoice and an invoice is automatically created for you.
For a quick look on how to place purchase orders, you can watch this short video.