I've been working as a freelance developer for about 3 years now, and I realized I don't use or even know about any SaaS targeting this segment that would be so useful for me that I would want to pay for it (which doesn't mean there aren't any, probably there are...)
Do you know any?
Not a pure-place SaaS, but I like Double Your Freelancing.
Here are a few tools I built for myself as a freelancer...
Freshbooks has typically marketed towards solo and small companies.
I still use their older version because I can automatically snail mail invoices too. Prints them and mails them from their facility / partner, I never have to print or mail anything.
Love it.
Yeah forgot to mention the only one I'm actually using is for invoicing, it's called Billingo.
I use it for every venture I get into though, not just for freelancing. For example I ran a few e-commerce businesses and integrated Billingo to automatically generate invoices on purchases.