TOPIC: good with java/android coding? 100m Reward

private Boolean firstTime = null;
	/**
	 * Checks if the user is opening the app for the first time. 
	 * Note that this method should be placed inside an activity and it can be called multiple times.
	 * @return boolean
	 */
	private boolean isFirstTime() {
		if (firstTime == null) {
			SharedPreferences mPreferences = this.getSharedPreferences("first_time", Context.MODE_PRIVATE);
			firstTime = mPreferences.getBoolean("firstTime", true);
			if (firstTime) { 
			    SharedPreferences.Editor editor = mPreferences.edit();
			    editor.putBoolean("firstTime", false);
			    editor.commit();
			}
		}
		return firstTime;
	}