The best way to make sure that a document scanner app is working properly is to allow it to access the camera of your device and the storage.

The app will then be able to perform the following functions:

A powerful and easy-to-use document scanner that can convert any text or image to a PDF file. 

It can do that in a few seconds and doesn't need any special skills to use. 

The app can save scanned documents in a folder on your device. 

It will work on Android devices, no matter their brand. 

This document scanner app allows you to use its basic functionality without paying a cent for it.