Map-Navigator Application Development

I'm looking for a skilled developer or team to create a map and navigator application. This app should be compatible with both web and mobile platforms, using open-source maps, preferably OpenStreetMaps. The application will have a dual purpose: allowing administrators to create named lists with geopoints, and enabling users to navigate to these points and find the nearest ones.

Key Features:
- Cross-platform: The application should work seamlessly on both web and mobile.
- Admin functionality: Admins need the ability to create named lists with geopoints. (i.e. Chinese food list)
- User functionality: Users should be able to navigate to these points and find the closest ones.
- Use of OpenStreetMaps: The app should be based on open-source maps.

Authentication:
- Social Media Login: The app should utilize social media logins for user authentication.

How to apply:
1. Web or mobile? which part can you cover and how good
2. Experience with OpenStreetMaps and other open-source mapping tools.
3. Technologies and strategy of how to build such service.
4. Your availability, budget and estimate time for it. (very important for it to be as much precise as possible)