Yes we integrate with both Online and Desktop versions of QuickBooks.
There is a fully automatic integration with QuickBooks Online. It allows you to import your customer information from QuickBooks and export your invoices to QuickBooks, you can find all the information you need here:
We also have a more manual integration available if you are using a desktop version of QuickBooks. You can still import and export your customer information and invoices, however it is not automatic, it is done manually as IIF files. You can find all of the instructions on how to do this here: