We have bought a plugin for Wordpress (js-appointment) that allows users to book an appointment and make a prepayment for the service selected.
However it currently has a few bugs aswell as needing a few extra features - .
The problems are -
If negative 'Total' amount (i.e. a coupon = more than the total) and you click book (with Paypal automatically selecting as the payment method) - Paypal brings up an error. So if the 'Total' is negative we need to remove the 'Choice your payment', as there is no payment due, and when Book button is clicked, the appointment needs to show as paid, as it's been paid for with the coupon.
There is an option to set the dates to and from i.e. from May 1st to May 30th, but if you select May 4th and then change your mind and select June 4th - it will allow you to continue to book, even though that date shouldn't be available.
We also need to the dates to be changed to UK format rather than US (i.e. d/m/y)
Also in the booking information, there needs an option to include an additional address i.e. the person booking the appointments address and the address of the person the appointment is for.
There are also some issues with google calendar sync that need looking at.
Hopefully this is enough information to help you accurately estimate this job.
Any questions, please ask.