Dudle - Dudle is an online scheduling application, which is free and open source.
Salon Ultimate - Salon Ultimate manages a salon or spa's employees, appointments, promotions, mailings, client data, and social networking from a single dashboard.
Pulse 24/7 - Booking & scheduling mobile app for service providers
SalX - Spa and Salon Management
MakePlans - Online appointment booking - MakePlans
Acuity Scheduling - Automate your client bookings, cancellations, reminders & payments using the worlds friendliest online scheduling software.