It's a great file manager that essentially allows you open "windows" so you can copy and paste between different storage media really easily. The icon UI is just easier to use than Google Files imo, because you can change the icon sizes. With google files you're just told "Either you get a list or a tile layout with only 2 columns, take it or leave it"

Looked high and low through the google play store and nothing I've downloaded and tried has dethroned this file management app just yet.