UpdateService.java

public class UpdateService extends Service {
    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        // generates random number
        Random random = new Random();
        int randomInt = random.nextInt(100);
        String lastUpdate = "R: "+randomInt;
        // Reaches the view on widget and displays the number
        RemoteViews view = new RemoteViews(getPackageName(), R.layout.updating_widget);
        view.setTextViewText(R.id.tvWidget, lastUpdate);
        ComponentName theWidget = new ComponentName(this, UpdatingWidget.class);
        AppWidgetManager manager = AppWidgetManager.getInstance(this);
        manager.updateAppWidget(theWidget, view);
        
        return super.onStartCommand(intent, flags, startId);
    }
}