Hiya,
Try Nutcache - <a href="http://www.nutcache.com/features/invoicing.html"</a>. It's completely free and is really easy to use. I have a small business and it takes a lot of the pain out of my invoicing, accounting, and time tracking.
They just launched a mobile app too, so you can track time and review your projects on the go.
Hope this helps!
Katie