Quickbooks does a great job of this if you take the time to learn it. Wonder if this ties back into it and automatically uploads to it so you don't have to re-neter the data? Invoices are typically the least of a Entrepreneurs list of things to be concerned with :). Getting their chart of account together and understanding how much a good set of books can help them is however very important. It helps you get credit and partners later on. Do you think this is app looking for an audience or an audience that really needs the app?