Mobilizon - A free and federated tool to get our events off Facebook
Live Chat by Sumo.com - Instantly communicate with customers, prospects & visitors
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
DownToMeet - DownToMeet is a platform to organize, find, and attend group events.
GoSquared Live Chat - Beautiful, simple, and free live chat for your website