If you're looking for a tool to synchronize your calendar across all your devices, Dola is a great choice. It's an AI-powered calendar assistant that can communicate with you through voice, text and images and that integrates with Google Calendar, Apple Calendar and CalDAV. That means your calendar is always in sync and easily accessible across all your devices.
Another tool worth a look is SkedPal. This calendar app uses artificial intelligence to schedule time blocks based on your priorities and reschedule when changes take place. It can integrate with Google, Office 365 and iCloud calendars, so it's a powerful tool for managing complex schedules.