Initial screen has weak call-to-action
A single checkmark (tick) looks like a status. Does it mean its booked? Oh, it's a button, and it means I can book.
For this to be intuitive I think you're going to need to use a word here.
Reported by: Jay Rogers
Yeah, would be good to update the UI. Some text like "Book me" in place of the checkmark could be handy.