Hey Landscape Poet,
You can find some additional documentation about our Expense Tracking Add-on here: http://docs.getjobber.com/expenses/
I would also encourage you to sign up for a free trial if you haven't already and then get in touch with us via our support channel to request a chat with one of our account managers. We're more than happy to set up a telephone call to discuss your specific needs and show you how Jobber can help.
Sam @ Jobber