Meetingbird for Gmail - View your calendar and schedule meetings right from Gmail
Clara - Clara is a virtual employee that schedules your meetings, getting you to the work that matters, faster.
Mixmax Calendar - The fastest way to schedule meetings with anyone, anywhere
Mastermind Manager - Software for running mastermind groups
Sunsama - Calendar and scheduling for teams
Schedulr - Schedulr makes it easy to meet with others w/out the headache of back-and-forth emailing.