Looks nice, although there's nothing compelling enough to switch from my current (Billings).
If you're looking for feedback, you should allow invoices to be emailed from within the app. This workflow would drive me mad: download pdf -> new email -> type address & subject -> attach pdf -> send.
We've held off emailing invoices through the app so far as we want to come up with a very good interface for it. Something that doesn't require lots of customization and mail merge handling, but is flexible as well.
But it's great to hear there's demand for this feature!
If you're looking for feedback, you should allow invoices to be emailed from within the app. This workflow would drive me mad: download pdf -> new email -> type address & subject -> attach pdf -> send.