Building an app with multiple crucial components:
1) Sign-in/Log-in screen
2) If new user, quiz with multiple questions that determine the user's preferences
3) Based on those preferences, rank companies and create a portfolio based on the user's preferences
4) Allow the user the ability to change their portfolio
5) Payment functionality (Stripe, etc.) for users to buy-in to the portfolio with their credit cards
The app has already been protoyped through ProtoPie, so the developer should be able to focus on the actual coding and not designing the app.
App quality is more important than price so please quote what it would take to build a high-caliber app with these crucial components. Feel free to reach out to me if you need more information or have follow-up questions.