Simple File Manager Pro
Current Version 6.1.0
Requires Android 5.0 and up
Content Rating Everyone
Updated February 16, 2019
Get it on Google Play
The fingerprint permission is needed for locking either hidden item visibility, or the whole app.
Contains no ads or unnecessary permissions. It is fully opensource, provides customizable colors.
This app is just one piece of a bigger series of apps. You can find the rest of them at https://www.simplemobiletools.com