Duuoo - Meetings that Matter
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.
Matter - Create a feedback-focused culture in Slack with Matter!
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Moodbot for Slack - A Slack bot tracking employee moods + actionable data
Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.