Hello, I am trying to make sure of exactly what you need. I think you are asking for a simple application that you interface with and enter information based upon your inventory and rental items? So you have 100 rental chairs, rent at $1 per chair, and $15 deposit. Your application will record the sale and the return date for the product. And then it will generate an invoice and save a record for tax or accounting purposes?? If this is what you are asking for please let me know. I can have this done very quick. My name is Joe and my contact information is 909-659-2446. Thanks and have a blessed day.