Mobile eInvoice Lite allows you to create customers and inventory on your iPad. You can also sale products and services to customers and collect credit card payments thru Authorize.net gateway services. Detailed Invoices are then mailed to the customer. You can see from the images that you start off with a Sale Screen, enter a new customer or select from a list, then select inventory (Taxable items as well and rate) and then enter the credit card info and simple submit, you get a response from Authorize.net of successful completion or message for anything that is declined (Bad Card Number, Expiration Date, NSF, etc.). The card is processed as Authorize AND Capture which means the funds are validated and the transaction is processed. See Authorize.Net for Service charges and fees for Merchant Accounts (You want to make sure you setup receipt emails as well). Please enjoy the application. Look also for Mobile eInvoice Pro for enterprise features.