Cron - Cron Calendar.
Heyday - An automatic journal that makes remembering beautiful & fun
Cal.com - Cal.com (formerly Calendso) is the open source Calendly alternative.
Duedot - Dossier collaboration platform
zcal - zcal is the fastest way to schedule every meeting for Free and make it personal.
Workgroups DaVinci - Project management and workflow automation software for marketing and creative teams.