Google Calendar - Spend less time managing your day & more time enjoying it
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.
Etar - Material design open source calendar for Android.
Acuity Scheduling - Automate your client bookings, cancellations, reminders & payments using the worlds friendliest online scheduling software.
Nextcloud Calendar - The Calendar app is a user interface for Nextcloud's CalDAV server.
Doodle - Make meetings happen. With Doodle, scheduling becomes quick and easy.