An associate of mine uses one. I meant to look into it but haven't got to it yet. This winter when the roofs are covered with that white stuff, I plan on either purchasing a program or just creating one myself. Ideally for me, I want a database where I enter all the customer's info. Then I simply click a button to create and email a quote. After the job I click another button to create and email an invoice/receipt.
New here. I had the same question a few days ago and after a lot of searching found that a lot of guys are using http://quickbooks.intuit.com/ for invoices. They will also send you a free card reader for your phone or tablet. I have not use it yet because I have not done a roof yet. But the program seem very user friendly and you can try it free for 30 days. Hope this helps. Again I'm new here and new to roof cleaning.