Location Tracking App Development

I'm seeking a skilled developer to create a location tracking app for personal use. The app should be able to accurately track the location of individuals by entering their phone number.

Key Requirements:
- Simultaneous development for both iOS and Android platforms.
- City-level accuracy in location tracking.
- User authentication via phone number login.

Ideal Skills and Experience:
- Proficiency in mobile app development for both iOS and Android.
- Experience with location tracking technology and ensuring accuracy.
- Knowledge of secure login systems using phone numbers.
- Familiarity with user interface design for a seamless user experience.

Please reach out with your portfolio and relevant experience.