eVetPractice - Cloud-based veterinary practice management system
Appointment Booking Calendar - With the Appointment Booking Calendar you can accept online bookings from a set of available time-slots in the calendar.
RxWorks - RxWorks is a practice management software that is centered on the electronic medical records for patients and allows to track all items associated.
Dudle - Dudle is an online scheduling application, which is free and open source.
Zendesk - Zendesk is a beautiful, lightweight help-desk solution.
MakePlans - Online appointment booking - MakePlans