Ultimate Member - The easiest way to create powerful online communities and beautiful user profiles with WordPress.
Appointment Booking Calendar - With the Appointment Booking Calendar you can accept online bookings from a set of available time-slots in the calendar.
Paid Memberships Pro - The complete membership solution for your WordPress site.
Dudle - Dudle is an online scheduling application, which is free and open source.
WP User Frontend - The Ultimate Frontend Solution for WordPress to let your users manage everything from Frontend!
Pulse 24/7 - Booking & scheduling mobile app for service providers