Storage Access Framework

[UjuiUjuMandan]

WRITE_EXTERNAL_STORAGE should be removed as soon as possible and replaced with SAF. This is one of the requirements to return to Google Play.

https://developer.android.com/training/data-storage/shared/documents-files

This library looks promising.

https://github.com/ChochaNaresh/FilePicker

[ningshanwutuobang]

This project would not have long term maintenance. And there is no plan for Google play. If you want to change it, you can add it by yourself.