The big feature here is Caldav support.<p>Calendly only works with Google and Microsoft - no planned support for any Caldav services like fastmail.<p>Fantastical makes a great calendar app with rock-solid support for virtually any calendar service. I hope this pushes Calendly to reconsider caldav support.<p>I should note Harmonizely has tried to step into this niche and may be very successful but I found the app to not have a stellar UX and a lot of calendar invites never made their way back to my inbox which completely defeats a calendar scheduling app in the first place.