Ask for what the app is missing. 150 companies behind a request earns a written answer from the developer within 5 business days — sometimes a yes, always a reason. The threshold is under review as the community grows.
Showing Shipped on Feature requests — clear
Customer signature on change orders from their own phone
I send the change order, they call and say "fine, do it". Nothing is signed and that is exactly the ticket that ends in a dispute.