I'm co-founder of a start-up in SF, we're developing an API that enables you to :
- detect if two phones with the same app are nearby, EVEN IF THE APPS ARE IN THE BACKGROUND
- exchange data with people around you
- send push notifications to users nearby.
Simple examples : - create a leaderboard based on the people you came across - whenever you make your high score, people around you that have the game get a notification with your high score. - exchange virtual currency
We believe a lot can come from this, and we're looking for beta testers !