Why does it cost money?

This app is great, but it’s not what I need. I already have 5 apps just like this.
I thought you could edit files, create new ones, etc., but it only lets you look at files and read them.
If it were what I’m looking for, totally fine, but other than that, why does such a simple app cost so much?

Zebeka about File View, v2.1.1