how to read/write data on Android?

[Nicolas Cueto]

> Sorry again, you're probably pretty frustrated by now.

Pretty. But not with you or your advice. Still most thankful for that.
Because now, thanks to your help, I finally got it all working. And
not only for reading but for writing data too.

Again, thank you!

P.S. Since my app's files don't seem to get listed in the Android file
explorer, can I assume that'd only work with unrooted Android devices?
--
Nicolas Cueto