User permissions problem

[demokedes]

Hello,
I am using mk808 (Mini Android PC). I have android 4.1 on it.
I also installed some additional applications. I have some problems with user rights.
For example. I installed rTorrent. It is simple torrent application.
When I download some files, I cannot access them, because by default all files that I download, have very limited rights (I think 2xx), only owner has read rights

 

[Davdi]

This page http://www.tuxfiles.org/linuxhelp/filepermissions.html explains Linux permissions very well.

 

[demokedes]

This page http://www.tuxfiles.org/linuxhelp/filepermissions.html explains Linux permissions very well.

Hm, that's true. In this article theory it is descrbied. But I think, Android has some specifications. How can I add user to specific group in android?