Looking for a developer who can implement my daughters dream app

The idea of the app is to build up your social network based on quick sharing of your social media accounts at concerts, festivals, business meetings and what have you. Location-based sharing of your social media accounts. So the way it would work is the following:

1. User1 switches on social media account sharing on his/her phone
2. Application published location data periodically to a central storage
3. User2 is in the vicinity (application calculates distance between User1 and User2) and sees User1 on his/her phone and wants to connect on social network
4. User2 sends request to share social media account to User1 using app
5. User1 receives request and approves or denies
6. If denied User2 gets denied message. If approved User2 receives User1's social media accounts

Enhancements:

• User1 selects which accounts to share to who
• User1 get automagically added to User1's profile on selected social network

Privacy: Not an issue since User1 consciously decides to share his/her accounts. This can be switched on and off at will.

Gotcha: I will NOT pay for the development. The idea is that someone picks up this idea and make it his/hers so the app is yours and if you become the next Mark Zuckerberg then you owe me nothing. I'm just dropping an ida here.

I've been looking around and a couple of things surprised me:

• Why is this not an integral part of Android/iOS?
• Why has nobody come up with the same idea? If you know of an application that already does this, please let me know.