Affordable Client/Server Point of Sale Systems for Busy Retailers. If you're looking for a Point of Sale system that will truly meet your needs...if you want a system that can greatly increase your profit while saving countless hours of work and making your life a lot easier, the Spirit POS is for you! The Spirit POS system includes a cash register and back office suite with inventory tracking, customer tracking, reporting abilities. All standard POS features are included, along with several features unique to the Spirit POS system