Controlling Your Business 40 is absolutely the easiest invoice or invoicing software. Its modular design is perfect for the user that needs to track important information without the complexity of some of the major financial packages. Helps you track Customers or Companies, Employees, Products, Inventory, Suppliers, Expenses, Things-To-Do lists, Invoicing, International Tax Config, Date, Phone, Postal formats, Searching, export, email, and more!