EventsBase - Find the best professional events nearby or globally
Rally by Eventbrite - Find the best local events and rally your friends to join
Leisure Time - Leisure Time is an Android, iOS, and Web App that allows users to find leisure time activities in their vicinity that might interest them.
Humbler - Find events that support causes you care about
Sporty - Beautiful app for creating/joining sports activities nearby
Alkarta - Find happenings in your city.