This App illustrates, how to access and manipulate app-internal and external android storage with apps designed in Android Studio. If you need to add a very simple file explorer to your App, you are free to base it on UrNote.
To learn more about the theory behind storage management in Android have a look at this seminar paper, which also mentions design patterns you may want to use in your app.
The images below show the UrNote FileEditor, renaming a file with UrNote, an overview of file system access points, the text editor and image viewer all as available in the app.
