Compare software

BusyCalThunderbird
Paid

Costs $49.99 USD after a free 14-day trial, and is also included in Setapp.

 Free

Free forever, funded by donations.

macOS, iOS Windows, macOS, Linux, Android
  • Works with iCloud, Google, Exchange and CalDAV
  • Highly customizable views including a Year Planner
  • Unified inbox across every account, or each account kept separate, your choice
  • Mail, calendar, contacts and tasks in one application rather than four
  • Apple platforms only
  • Paid after the trial
  • The interface carries a lot of history and can feel dense next to a webmail tab
  • Major ESR releases have historically been disruptive for add-ons and settings
Downloadable app Downloadable app
Closed source Open source
License not stated License: MPL-2.0
Not stated if an account is needed No account needed
Not stated if it works offline Works offline

Checked September 23, 2026

Checked September 20, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.