Creating instance in Application class

Question

I am developing an Android Application, in which I am using Network libraries Retroift with GSON,Otto and Realm. So am creating instance in application class( extends Application). It makes my app launching time very slow. Is there any alternate solution to solve this out.

 public class MyApp extends Application{

     private MyApp appInstance;
     private MainThreadBus bus;
     private RealmConfiguration myAppRealmConfig;
     private GSON gson;
     private HttpLoggingInterceptor logging;


     @Override
        public void onCreate() {
            super.onCreate();

            //Application instance
            appInstance = this;
            gson = new GsonBuilder()
                    .setDateFormat(ApiConstants.API_DATE_FORMAT).setFieldNamingPolicy(FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES)
                    .serializeNulls()
                    .create();
            mAppRealmConfig =   RealmConfigurationFactory.createMyAppRealmConfiguration(this, secretKey);
            appConfig = new AppConfig();  logging = new HttpLoggingInterceptor();
        logging.setLevel(HttpLoggingInterceptor.Level.BODY);
        bus = new MainThreadBus();

    }

   public Gson getGson() {
        return gson;
    }

    public AppConfig getAppConfig() {
        return appConfig;
    }

}