Easy Order Manager+

the peeps here at Easy Invoice make life with Shopify Invoices just that ... EASY. Since I've been using this app (about 2 years now) they've added considerable functionality like editing your invoice if you wanted to include more details as well as printing, saving as .pdf to email, and a host of other things. You'd be crazy not to give this a go and find out what great customer service they provide as well. That alone to me in *priceless*.