This is an interesting idea, and I like your site design.

You have two types of users, the business owner who offers appointments, and their customer. You've done a nice job showing what the end customer will do to make an appointment, but you haven't explained what the business owner will have to do to get set up. The business owner is the one making the decision to use your service. I would change the How It Works section on the main page to be from their perspective, and keep the current How It Works to show what their customers will see.