World Time Buddy works well for proposing meeting times (particularly useful while traveling); shows exactly what time it is across up to five time zones.
Doodle.com is a long-time favorite of mine (and free!) that is best at coordinating an event with a large number of people: people vote on when they are free and the tool shows you which day/time the most people are available.
Calendly (my favorite) and ScheduleOnce – Online appointment scheduling made easy, with lots of additional features as you move up in pricing plan (though you can get a solid set of features just starting at $5/mo)
Uber Conference — for $10/mo get your own phone number (no password needed), record calls, and get text messages if your guest is on the line before you, in case you forget you have a call scheduled (I have done this more than once!)
Satori– More sophisticated streamlined system build specifically for coaches to help with all aspects of business, particularly new client intake, scheduling, and invoicing. Plans start at $25/mo.
