Raft Calendar - A fun and beautiful calendar for couples and close friends
Google Calendar - Spend less time managing your day & more time enjoying it
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Mixmax Calendar - The fastest way to schedule meetings with anyone, anywhere
emble - Plan better events with your friends
Clean Google Calendar - Makes Google Calendar look nicer & launches as a desktop app