Q:

Can mobile apps access the phone's settings?

I had an idea for an android app that would need access to the phone's settings. I am not sure that the app would be able to change any settings (such as screen brightness or turning on wifi).

A:

yes you can acces to such things,
change screen brightness:
 android.provider.Settings.System.putInt(getContentResolver(),
                android.provider.Settings.System.SCREEN_BRIGHTNESS,
                value);

add this to manifest
<uses-permission android:name="android.permission.WRITE_SETTINGS"/>

turn on wi-fi
WifiManager manager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
manager.setWifiEnabled(true);

add this to manifest :
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />

