I have used bean cruncher for about 6 months now. I use it mostly to help my clients keep track of expenses and invoices. It has the ability to generate invoices and receipts automatically and it works with my clients accounting software so I don't have to manually enter any information. It has a nice interface and is simple to use. It will give you an estimate of how long it will take to complete a project and when you submit the invoice it generates a receipt. It is relatively cheap and the program is free to try out. You can pay monthly or yearly for the premium version.