Calendify - Calendify is an event community where you can share, publish, and subscribe to event calendars. It helps you to stay informed about what you are interested in and what is yet to come.
EventsApp - A simple concise app for creating and sharing events.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Eventjoy - The Easiest Way To Organize An Event
Meetup for iOS and Android - Discover groups that are all about the things you love
Facebook Local - Discover places to go and events happening near you