Why are there paid apps in the free section?

Lately I've been looking at the App Store a lot and one of the things that have surprised me the most is the appearance of paid applications in the Top Free. So I thought, why would there be paid apps in the free section if everything is controlled by logarithms and algorithms? And then I found the key. If you want to know why paid applications appear in free sections on some devices, you just have to read here.

What seems like an Apple failure with paid apps ... it is not

Well, as I was saying, I observed that there were paid applications in the free section of the App Store; then I looked and found the following characteristics:

1. All the paid apps that appeared were from Apple
2. I entered the applications that were supposed to be paid from my computer and in truth, They were free
3. I tried with another iPad 2 (same as mine) and the same problem also appeared

So… I found the key. All the applications that were paid had been made free in iOS 7, as long as we had a new device. My iPad, being a second-generation one, was not included in the "promotion" of new devices, so all the applications that were "free" for me were paid.

It would be very complex to have two App Stores that only transferred the free Apple apps (for new users) to being paid (for users with "old" devices). Apple should have warned about this because surely it has happened to more than one and has not found the solution to the problem.

So now you know, if you see paid apps in the "Free" section of the App Store, surely they are big apple apps like Garageband, Pages, Keynote ... which are only free for new devices.