When im on my computer, i can open a opportunity and on the left hand side it shows a payments tab which i can open and then send a invoice. This feature is unavailable in mobile app and causes a problem for our sale process. We basically have to use high level one way on the computer and then use a entirely different process on the phone which can be a problem for keeping things in order and tracked properly. It would be AMAZING if we could send the payment there in the opportunity OR when going to the payment section in the app if there was a option to assign the invoice to a specific opportunity.