Design a Solar App that populates from an Excel file

MY APP VISION: We have solar sales representatives that sell door-to-door with tablets in their hands. I'd like them to be able to open this app and create a quick estimate of the system costs. They don’t need to sign in, although it would be nice for the proposal to have their phone number. Let's call it "True Energy" - that's the name of our company. Once the app is open they can talk to the customer and find out 1) the customers name 2) their address 3)their yearly usage in kwh and 4)their monthly average bill (these are highlighted in yellow on the first page of the excel). Then they'll input that into the app, hit submit and the proposal will pop up. It will look like the Proposal attachment, but have all the numbers populated from the excel. I'd like them to be able to save this page as a pdf, because then the customer could Docusign the proposal with Adobe software and the sales rep could send the customer a copy.