// The app group must be set up first
await SharedPreferenceAppGroup.setAppGroup(appGroupID);

// Set values using [[NSUserDefaults alloc] initWithSuiteName:appGroupID]
await SharedPreferenceAppGroup.setBool('MY_BOOL_KEY', true);
await SharedPreferenceAppGroup.setString('MY_STRING_KEY', 'STRING_VALUE');
await SharedPreferenceAppGroup.setInt('MY_INT_KEY', 42);
await SharedPreferenceAppGroup.setDouble('MY_DOUBLE_KEY', 9.9);
await SharedPreferenceAppGroup.setStringList('MY_STRING_ARRAY', ["element1", "element2", "element3"]);

// Get values
bool boolValue = await SharedPreferenceAppGroup.getBool('MY_BOOL_KEY') ?? false;
String stringValue = await SharedPreferenceAppGroup.getString('MY_STRING_KEY') ?? 'null';
int intValue = await SharedPreferenceAppGroup.getInt('MY_INT_KEY') ?? 0;
double doubleValue = await SharedPreferenceAppGroup.getDouble('MY_DOUBLE_KEY') ?? 0.0;
List<String> stringArrayValue = await SharedPreferenceAppGroup.getStringList('MY_STRING_ARRAY') ?? [];