Backport app to lower Android versions

[czlucius]

Is your feature request related to a problem? Please describe.

Current minimum Android version is about Android 6. Other users may have older versions and hence cannot use this app.

Describe the solution you'd like

Backport to lowest Android 4.4(support for Storage Access Framework) (and Google dropped support for 4.1 few months ago...)

Describe alternatives you've considered

N/A

Additional context
Add any other context or screenshots about the feature request here.