Dudle - Dudle is an online scheduling application, which is free and open source.
Zoho Meeting - Free video conferencing, online meeting, desktop sharing solution from Zoho.
Pulse 24/7 - Booking & scheduling mobile app for service providers
Airtime - Hang out with group video, share music & videos
Time Slot Booking Calendar PHP - Time Slots Booking Calendar PHP for online appointment booking and class scheduling.
Voxox CloudPhone - Get a local or toll-free business number that automatically answers, routes and transfers calls, plus other professional business phone services.