For what I wanted to do, this looked like the right app to purchase so I did. I have to admit, this is a very slick setup and is great for what I needed; to be able to set up appointments in 10 minute increments.
Much to my chagrin, though, to set up 10 minute appointments for one event on one Saturday is possible, but to block out other Saturdays, the admin would have to go through all those 10 minute appoints (45 of them in a day in my case) on all the other Saturdays to keep people from signing up for times you are not available. And there is not a way to wholesale block them out by an admin.
Also that there is not a way to change the bookings to check boxes for multiple people in a group, which is another function I would need.
The perfect scenario would be if this was adjustable by DATE not by day of the week. I give it 4 stars because it is almost there and I am very impressed, just disappointed I cannot use it as I had hoped.