Cal.com - Cal.com (formerly Calendso) is the open source Calendly alternative.
Kyber for Slack - All-in-one Slack app: tasks, standups, polls, surveys & more
Cron - Cron Calendar.
Huminos - Free OKR and Growth acceleration platform for Startups
Calendly - Say goodbye to phone and email tag for finding the perfect meeting time with Calendly. It's 100% free, super easy to use and you'll love our customer service.
Meetingbird - Powerful meeting scheduling and notes — right in your calendar