TidyCal

Up: Very easy to use, has a good clean look, customizable URLS, and just about all the features you could want. At this incredibly low price, it's such a good value for a new business with a tight budget. I appreciate TidyCal.

Down: The one feature I wish it had is a discount code feature for paid bookings.

My only other issue is one you have to take with a grain of salt, because at a price like this, you know support will not be as robust as with a more expensive option. I'm eight days in though, and although I put a ticket in five days ago, I haven't heard anything back yet. The calendar invites the system sends out are instantly rejected by the recipient's email server, so I've had to manually work around that issue.

So, if you're in the market for a booking app, this is almost guaranteed to be the best one to buy. It's miles ahead of the one you get from Microsoft and Google, it's a much better value than Calendly or similar, but you should set it up and test it well in advance of when you will need it so you can iron out any issues you might have getting started.