Detour - Immersive audio walks, now in 17 cities
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Photo Find - Navigate to the exact spot a photo was taken
Facebook Local - Discover places to go and events happening near you
NoFilter - Discover great photo locations all over the world.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets