Quickest first: Help inside the app (left-hand menu), then these help pages, then the feedback form, then email.
Put these in your message: what you were doing, what you expected and what happened, your version number (Help → About), and a screenshot if it's easier.
Please don't send a customer's drawing. Describe the problem, or recreate it with a simple shape of your own.
Everything is set up to run on your own, and if you're stuck, a person answers your email.
For invoices or legal matters, see the terms of sale.
Job Shop Office is a product of Zimora Group LLC, Pennsylvania.