HollaBack is a chat app that allows people within a 15 mile (25 km) radius to be able to send messages to each other based on specific #keywords that fit their interests.

Having a #YardSale this weekend? Broadcast it to your neighbors.

Found a great #deal? Share with others in the area who might be interested.

Looking for a #restaurant with great #vegan options while visiting a town? Ask the locals.

Create a list of keywords to watch for that will appear in a "Focused" tab when someone nearby sends a message containing the keyword(s).