There is a free version, but to get the calendly branding removed, integrate with apps, and to use SMS messaging, it’s $12/month
Free version, but $17/month to get all integrations. Button isn’t super cool, but the pop up is kind of slick. They have their own mobile apps if you want to use them as well. Facebook/Instagram integration too.
Not quite as geared to classes, but I think I can get it to be more manageable if I work on it a bit more. I only added one class type for now and didn’t work the hours too much. It’s pretty and customizable. $10/month