Can I put an idea to you for an improvement.
When I look at all my invoices I would love to be able to filter by month. This way I can see quickly at the bottom the values I am due in or the values I have sent out.
So You could filter by job and month, by client and month, by status and month etc.
At the moment I need to get the calculator out and see all invoices then add up the ones within that month.