WebRezPro - WebRezPro offers property management system [PMS] for properties of all types and sizes.
MakePlans - Online appointment booking - MakePlans
Track - Track is a cloud-based hospitality software to run your business, take bookings, accept payments, track marketing and calls, & manage revenue from anywhere.
Appointment Booking Calendar - With the Appointment Booking Calendar you can accept online bookings from a set of available time-slots in the calendar.
HotelFriend - Avoid COVID-19, keep your staff & guests safe, respect social distancing. Be prepared, get ready to open your hotel any time with HotelFriend Solutions.
Dudle - Dudle is an online scheduling application, which is free and open source.