Brilliant

Super easy to install, configure and use. You can install the plugin automatically using the Plugin install by searching for the plugin by name. Activate and it will appear in the settings bar on the right hand side. Simply configure with the Services you wish to offer, you are able to make additional categories for services within several departments and create appointment slots based on time frames from as little as 30 minute session. An email is also sent to the registered email address for confirmation. You will also need to create a page to include the shortcode and add this page to your menu for it to appear.

This was the 4th plugin I tried for this service and love it so far.