Shopify Order Printer

I'm based in the UK and couldn't find a good way to generate an invoice for a customer after taking payment. Most business customers will request this for their records.
This is really handy because I can easily customise the template to make it UK-compliant. Now I can easily print to pdf to create an invoice that I can email on demand.
I'd give it 5 stars if it was integrated with the order page.