Cross-Platform Offline Navigation Mobile App

I'm looking for an experienced mobile app developer to create an offline navigation app for both iOS and Android platforms. The app should utilize Google maps and incorporate key features like turn-by-turn navigation, Points of Interest (POI) search, and offline map download.

Key Requirements:
- Cross-platform mobile app development experience, particularly with iOS and Android
- Proficiency in integrating Google maps into a mobile app
- Previous work experience in developing navigation apps
- Understanding of implementing features like turn-by-turn navigation and POI search
- Skills in enabling offline functionality for map downloads

Ideal candidates will have a portfolio of similar projects and strong references.