Opening accounts receivable is not very friendly at the moment. If I want to add a receivable invoice al I can do is add a balance to an account. So if I have an invoice with GST i need to add amount of GST to that account, save and another to whatever income account is used. This creates 2 invoice for to be deposit to be assigned to. If you made a mistake for example GST went to the wrong account, you cannot adjust it, and making a journal entry to adjust it doesn't work because it goes to the current year, not to the previous year.
Might be good to make it a bit more user friendly