No demo and you don't want money... I'd say that your only missions is to get them excited about what you're building, ask for their sage advise, and get permi

No demo and you don't want money... I'd say that your only missions is to get them excited about what you're building, ask for their sage advise, and get permission to contact them about the app once you have something to show (a biz plan, a demo, etc). But focus on the advice. Ask questions like "Do you think we're focusing on the right problem?", "What do you think we should do differently?", "Should we get a business plan together or focus on our demo?", etc. You want to vet this individual for their brain, their interest, and their wallet. :-)