Zoho Bookings - Online scheduler for offering the best consultations
Dudle - Dudle is an online scheduling application, which is free and open source.
vCita - Online client engagement solution, convert website visitors to clients, free customizable contact form, free online appointment scheduler.
Appointment Booking Calendar - With the Appointment Booking Calendar you can accept online bookings from a set of available time-slots in the calendar.
Acuity Scheduling - Automate your client bookings, cancellations, reminders & payments using the worlds friendliest online scheduling software.
MakePlans - Online appointment booking - MakePlans