Someone sent me a link to FastDue, which is intriguing as well. It’s got the same kind of invoicing capabilities and also lets you accept PayPal. But the coolest thing is that it contains a library of business document templates, such as contracts, non-disclosure agreements, etc. People are always asking me where to get agreements, and I like that they’re right here in the system.
FastDue is free for now — they pay for themselves with ads. I read they may switch to a standard/premium structure, which I would guess means you may be able to choose not to have the ads.