How do I mark something as a favorite, and what is it for?
You can mark a student, session, class type, location, fee type or product as a favorite in the ⋮ menu of its profile with the Mark as favorite row, and an exercise, block or message template in the ⋮ menu of its edit page. You can also mark any of them by long-pressing its row in the list, and remove it in the same place. A favorite shows a small star in the list and, where there is a profile, at the top of it.
When you pick something, for example a class type and location for a new session, a fee type for a payment, a product for a sale, an exercise for a session or a template for a message, your favorites come first, and they sit at the top of their own list too. For fee types, the favorites are followed by the most recently used. When you pick a student, the favorites among the names offered move to the front. The Favorites only button among the filters of most lists shows just them.