I also ran into similar problem and found out that 2 things should be done:
- path to settings file should be specified
- QSettings::sync() should be explicitly called after every settings change.
So on Windows I had this working:
QSettings settings("settings.ini", QSettings::IniFormat);
settings.setValue(GRID_ENABLED, enabled);
On Android I have to use the following code:
QSettings settings("/sdcard/settings.ini", QSettings::NativeFormat); //can be IniFormat, no difference
settings.setValue(GRID_ENABLED, enabled);
settings.sync();
Probably using "sdcard" is not good enough and you should use other directory.