The product itself looks really nice, but the pricing model doesn't really seem like a good fit. I think a freemium model would work better than a subscription based one.
The pricing model is a discussion in and of itself, but it boils down to us wanting Ding to be as simple and straightforward as possible. If you think the product is worth paying for after 45 free days, you either sign up for the Solo or the Team plan, and that's it. No annoying 'project limits' or anything like that.
There's a lot of theory on this subject matter, but we prefer to stick with what we think is a clean approach. At least for the time being.
From the work so far, I look forward to what they could do to simplify invoicing.
There's been quite a few requests regarding invoicing, and while I won't promise anything in the short term, we'll work hard to make Ding better in the future. People requested a start/stop-timer which we just implemented, so we do listen and take your feedback seriously.