FooSales is a secure point of sale (POS) system for WooCommerce that turns any computer, iPad or Android tablet into a cash register.
FooSales makes it easy to sell your products and run your business from anywhere in the world while automatically updating your WooCommerce product inventory, orders and customer data. It allows you to manage and process physical orders on-the-fly by connecting directly to your WooCommerce database. FooSales for WooCommerce is perfect for retail stores, markets, pop-up shops, mobile events and many others.
From the blog