Meetsy
Create your own polls - Terminplaner 4.1
Easy!Appointments – Open Source Appointment Scheduler
GitHub - jekuer/add-to-calendar-button: A convenient JavaScript snippet, which lets you create beautiful buttons, where people can add events to their calendars.
PeachPay - Monetize your Content
iCal Exchange
Calendly - Scheduling appointments and meetings is super easy with Calendly.
Twitter Analytics
Twitter for Business
Booked Scheduler - Free Trial