Google Calendar - Spend less time managing your day & more time enjoying it
24me - Next Generation Personal Assistant
BusyCal - powerful calendar app for macOS
WeekCalendar - WeekCalendar is an all-in-one calendar application designed to provide everyone with all the features they need to work to their fullest.
SmartDay - Integrated organizer with automatic scheduling.
Calvetica - The fast calendar for iPhone. Add an event in just two quick taps.