Great list of tools !

Here is one more tool that you may consider i.e. Invoicera. It is an online invoicing solution helps to simplify the process of account receivable and management. It allows you to create and send invoices for free.

not sure if I ever found an invoice application that supports more than 20 global payment gateway. I personally use Paypal but considering the fact that in most of the countries, businesses mostly relies on local payment gateways and Invoicera does offer them option to integrate their local payment gateway while invoicing to their clients.

Nice interface and cool features... have tried almost all the top invoicing apps so far, however, Invoicera has something that others do not have. I am 100% satisfied with the service of Invoicera and it is really saving lots of ma time.

loving Invoicera for its time tracking and invoicing capabilities... am an basecamp user and using Invoicera for time tracking and invoicing of my projects. I am happy to say now that my all projects are on right track and I am more than satisfied now using Invoicera. Cheers!

I have been used Zoho invoice in the past, but then switched to Freshbooks and have been using it since then. Honestly was not very impressed or satisfied with its service. I have signed-up for a free Invoicera account and have been blown away with its service. Soon would be purchasing it for my small accounting firm.