Kashoo is the best alternative to Quickbooks/Freshbooks out there,
if you are ok with the drawbacks listed - you will not regret!
Their team has been extremely helpful not only for technical questions - but also
for some Accounting best practices.
We haven't tried migrating from another vendor, though I am sure Kashoo's team will help you on that.
If you are choosing your accounting software for the first time - say bye bye to Quick books and the other crap out there - and say hello to Kashoo! Review collected by and hosted on G2.com.