Meeter - Hop in and out of calls, directly from your menu bar
Fantastical 2 - Fantastical, the Mac calendar app you'll enjoy using. Quickly create new events with natural language input and more.
Google Calendar - Spend less time managing your day & more time enjoying it
BusyCal - powerful calendar app for macOS
Calendar Widget: Month - Calendar Widget: Month is a significant calendar app developed and published by Candi Apps.
Superpowered - Power through the day without your calendar