Finding a time that's good for everyone to hop on a call or participate in a meeting often turns into a bad game of email tag. Calendly makes scheduling super simple, by coordinating your availability with others'.
Connect your Google Calendar to the site and Calendly will know when you have events marked as busy. Then you can share a link to your Calendly page and your invitees can schedule their own appointments with you, working around those busy/unavailable times. The invitees never have access to your dashboard showing all your appointments, but they can choose from various appointment types -- 15, 30, and 60 minute meeting intervals. You can add, delete or customise these event types.
By default, Calendly assumes a 9-to-5, Monday to Friday availability window in your time zone, but you can change your daily availability in the event settings. Other settings let you add a buffer before or after any meeting, specify a specific date range when you're available, and set up email reminders.
The service is free and great for one-on-one meetings. It could also come in very handy for service providers so clients can easily make appointments with you. To get group scheduling, however, or to remove the Calendly branding, the service costs $US10 a month.