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The easy to use free WordPress appointments plugin WP Appointments is packed with lots of innovative features that are rarest to be seen elsewhere. For example, both the front end and back end layouts are based totally on AJAX to give a seamless streamlined user experience. The ease of use goes beyond bounds. It can be used for a great variety of websites, such as doctors, spas, saloons, mechanic, personal trainers, lawyers, cleaning services, and so on. The outlook is high interactive and user friendly.
Features:
<iframe loading="lazy" class="youtube-player" width="750" height="422" src="https://www.youtube.com/embed/u_smM0ObkDU?version=3&rel=1&showsearch=0&showinfo=1&iv_load_policy=1&fs=1&hl=en-US&autohide=2&wmode=transparent" allowfullscreen="true" style="border:0;" sandbox="allow-scripts allow-same-origin allow-popups allow-presentation allow-popups-to-escape-sandbox"></iframe>
<ul>
<li>Totally AJAX-based Frontend & Backend</li>
<li>Interactive design with inspiring graphics</li>
<li>Multipurpose utility </li>
<li>Easy & quick installation</li>
<li>Auto Template Generator included </li>
<li>Email Template Builder </li>
<li>Managements of multiple locations or branches </li>
<li>Management of multiple services</li>
<li>Management of multiple workers</li>
<li>Extremely flexible timetable with time slots management </li>
<li>Fully device optimize layout</li>
<li>Translation support</li>
</ul>
Pro Version:
Pro Version of Wp Appointments is up for sale on CodeCanyon with countless extra features. Pro Version is covering 8 niches and more are on their way. In the pro version you can manage appointments, bookings, locations, services, team members, timetable, payment gateways and users. 
<a href="http://codecanyon.net/item/wpappointments-paid-appointments-system-wp-plugin/14480806" rel="nofollow ugc">Upgrade to Pro Version</a>

Wp Appointments

With totally AJAX based front & back ends, WP Appointments is a fully managed and flexible tool for building powerful appointments systems.

dvlyon

You will require a Musubi Account and to set-up your schedules with Musubi Bookings before using this plugin.

Musubi Bookings Plugin

You will require a Musubi Account and to set-up your schedules with Musubi Bookings before using this plugin.

Wp Appointments vs Musubi Bookings Plugin