The designer for ballpark is definitely top-notch - the folks over at metalabs are good at what they do. Keeping invoicing sexy is something that is hard to do (but we're trying our best as well!)
Congrats on the launch - I'm sure the folks over at FreshBooks (who are the obvious market leaders) are taking notice at all these invoicing/time-tracking apps hitting the market (cashboard, invoicemachine, letsfreckle, among others). It certainly speaks for how far we've come in Rapid Development and how accessible good UX/design has become.
We do take notice. It's good to see a lot of other apps come into the market with different ideas and approaches. It's definitely no good to end up in a market of one.
P.S. Andrew, it's too bad we didn't hook up when I was out in Victoria last summer. Are you coming to Toronto any time soon, by any chance?
Lu, similarly, I was just in SFO in January but I didn't reach out. My bad. Next time I'm down, shall we have a beer?