I've been dabbling in Evernote for a couple of years and wanted to see, if this could be a poor man's way to track Invoices Paid/Unpaid. I created a Template that will allow me to enter a new invoice once it's been accepted. This data will be synced to my phone and any other computers that have access to my Evernote account. I then created two Search Shortcuts that show me all Invoices that have been Paid and that have Not Been Paid.
These two shortcuts are at the top of my Evernote window and can be toggled on and off very easily. If you're using a dedicated accounting software, then this would not be a necessary option, but if you wanted to capture your invoice data and then be able to track it on any of your devices, then this might be an option.
Evernote is such a powerful tool, that is way beyond the scope of this post, but if you want to enhance the way to store, track and search for your documents, then this may be the ticket you have been asking for. Here's a screen shot of my template in Evernote:
My favorite use for Evernote is to be on a website and save the webpage or a portion of the page to an Evernote folder for future reference.