Mixmax Calendar - The fastest way to schedule meetings with anyone, anywhere
Lightning Calendar - Organize your life — it’s about time!
Calendly for Chrome - Schedule meetings without leaving your inbox
Simple Calendar - A simple calendar with events (optional recurring and reminders), week numbers and a customizable...
Polymail Calendar - Schedule meetings instantly over email
GMinder - GMinder is an open source Windows System Tray app that pops up to remind you about Google Calendar events.