Public Transport GPS Tracker App & Site

I'm aiming to develop a comprehensive app and website for my public transportation business with a core focus on real-time bus/train tracking. The tracking feature has to be GPS-based. Users should be able to locate and track buses and trains in real-time.

Ideal candidate should have:
- Expertise in GPS technology integration
- Experience in Android/iOS App and web development
- Understanding of public transportation systems
- A strong portfolio of relevant work.