Use Material Design and Standard Practises for SettingsActivity
Currently, the SettingsActivity is written by hand and difficult to extent. It does not use Material Design like the rest of the application (will).
It should be rewritten using best practices.
If for some reason, the preferences should not be stored in the default Android location, a custom PreferenceManager needs to be implemented.
To upload designs, you'll need to enable LFS. More information