Plan - Plan is a better way to organize.
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Streaks - The to-do list that helps you form good habits.
Event Hunt - Startups and Tech Events Curated By Locals
Taskful - Deadlines, meet your match.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets