No, your clients don't need to create an account in order to schedule with you.
When an appointment is scheduled, we send an email to your client with a private linkto the event page.
On this page they can easily add the event to their Google calendar, Yahoo calendar or another calendar by downloading the .ics file.
We do however make it easier for clients to book the second time around. Form data is saved on their computer so that clients won't need to re-enter contact information when they schedule with you again.