Nah not for that. There's a few different metrics at play. Notice it's in the free pile, so you're going to see things like Netflix in that category.
You also have to remember that literally anyone can make a Roku channel. It's not going to take a lot of downloads to get in the list. Check out that graphic. Youtube has 171,000 reviews. That's a TINY number of Youtube's overall traffic. So even if that JW app gets 100K or less downloads, it will show up in that list.