oorja - Your Dedicated Meeting Spaces Online — no installations
Simple Calendar - A simple calendar with events (optional recurring and reminders), week numbers and a customizable...
DejaOffice - Super-charged calendar, contacts, tasks and notes apps for Android, iPhone and iPad.
Lightning Calendar - Organize your life — it’s about time!
Stash - Free Sketch resources, redefined.
Calendar Lock PEA - Calendar Lock PEA is an encrypted desktop calendar with a day, week and month view. The shown calendars are never stored unencrypted on your disk, but exist only in the RAM. Platform-independent, Open Source, no installation or registration required.