POSIM is a point-of-sale system with inventory management that offers features such as quick checkout, credit card processing, special orders, discounts, recurring billing, and eCommerce integrations. It also has inventory management features that allow for adding single items or uploading thousands at a time, tracking serial numbers and service and repair, and using a style matrix for unlimited variations under a single item style. POSIM provides robust reporting for real-time insights into customers, sales history, and inventory. It is compatible with Mac, PC, and iPad and offers a free trial.