Mobile App Error Fixing

I need a mobile app built with Expo to be debugged and errors fixed. The app is intended for iOS and is currently a prototype, but it's not functioning correctly.

The app currently has:
- Crashes or unexpected shutdowns
- UI elements not displaying correctly
- Features not functioning as intended

Requirements:
- Identify and fix existing errors
- Ensure the app runs smoothly on iOS through Expo

Ideal skills and experience:
- Proficiency in Expo and React Native
- Experience with iOS app debugging
- Strong problem-solving skills

The goal is to have a working prototype ready for an investor presentation.