LightSpot

Lightspot lets you rent out your mobile data connection for money. Or you can purchase wifi access from someone nearby.

This is a proof of concept app showing how easy it could be for someone to discover and use someone else's data connection and pay for it with lightning.

Lightspot uses Google's Nearby API to discover those around you with a combination of bluetooth, wifi direct and sound. So for the buyer it works completely without initial internet access.