Time Slot Booking Calendar PHP - Time Slots Booking Calendar PHP for online appointment booking and class scheduling.
eVetPractice - Cloud-based veterinary practice management system
Dudle - Dudle is an online scheduling application, which is free and open source.
RxWorks - RxWorks is a practice management software that is centered on the electronic medical records for patients and allows to track all items associated.
Pulse 24/7 - Booking & scheduling mobile app for service providers
Zendesk - Zendesk is a beautiful, lightweight help-desk solution.