Windows Contacts - Windows has many extraordinary organizers, and in the event that you include distributed storage, then you presumably have more.
Calendly - Say goodbye to phone and email tag for finding the perfect meeting time with Calendly. It's 100% free, super easy to use and you'll love our customer service.
Flexibits - Makers of Cardhop, Chatology, and Fantastical.
Acuity Scheduling - Automate your client bookings, cancellations, reminders & payments using the worlds friendliest online scheduling software.
Apple Contacts App - Access and edit your contacts from personal, business, and other accounts with the Contacts app.
Doodle - Make meetings happen. With Doodle, scheduling becomes quick and easy.