Easy Invoice (PDF generator) produces all your estimates, sales invoices and receipts in PDF format and sends them direct to your clients. Sync between iPhone and iPad, or with Easy Books, our full bookkeeping package. Entering sales information into the app is quick and easy (as you might expect). You can define products you sell and their standard selling prices, even using quantity pricing if you want to. Then simply edit the customer details to match your own customer, and add as many more customers as you like.