Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Navver - A navigation app with live weather radar.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Dark Sky - Hyperlocal weather information, now on the web ⛈
Bigtent - BigTent is a web-based organization and communication portal for groups.
World Weather Info - New weather service, where you can not only check the weather forecast, but also take part in its creation.