What is the difference between Top Grossing and Top Paid in the App Store? In App Store, What is the different between Top Grossing and Top Paid?
There are three categories: Top Free, Top Paid, and Top Grossing.

In the Top Free category, the apps with the most downloads that have a price of $0 make the list.

In the Top Paid category, the apps with the most downloads that have a price greater than $0 make the list.

The Top Grossing category lists the apps with the highest total revenue (that is, price * quantity sold + revenue from in-app purchases). A $50 app is likely to have fewer downloads than at $0.99 app. The Top Paid list will likely include many inexpensive apps that get purchased often. The Top Grossing category is to indicate which apps have the highest total spent on them.