Really slow starting

Ionic Framework ionic-v3
1

My application starting after 20-30 seconds on android. Why?
YouTube

Its not bug for all devices, but this problem is popular in different sizes.
My own device starting after 5 seconds.

You can see my app: play.google.com

P.S. Sorry for my eng.

2

Can you run ionic info from the root directory of your project?

Are you adding the --prod flag when building your application?

3

ioinic info:
Cordova CLI: 6.3.1
Ionic Framework Version: 2.0.0-rc.5
Ionic CLI Version: 2.1.18
Ionic App Lib Version: 2.1.9
Ionic App Scripts Version: 1.0.0
ios-deploy version: 1.9.0
ios-sim version: 5.0.11
OS: macOS Sierra
Node Version: v6.9.2
Xcode version: Xcode 8.2.1 Build version 8C1002

plugins:

com.verso.cordova.clipboard 0.1.0 “Clipboard”
cordova-plugin-admobpro 2.25.0 “AdMob Plugin Pro”
cordova-plugin-compat 1.1.0 “Compat”
cordova-plugin-console 1.0.4 “Console”
cordova-plugin-crosswalk-webview 2.1.0 “Crosswalk WebView Engine”
cordova-plugin-datepicker 0.9.3 “DatePicker”
cordova-plugin-device 1.1.3 “Device”
cordova-plugin-extension 1.5.1 “Cordova Plugin Extension”
cordova-plugin-file 4.3.0 “File”
cordova-plugin-file-transfer 1.6.0 “File Transfer”
cordova-plugin-google-analytics 1.6.0 “Google Universal Analytics Plugin”
cordova-plugin-inappbrowser 1.6.1 “InAppBrowser”
cordova-plugin-inapppurchase 1.0.0 “In App Purchase”
cordova-plugin-network-information 1.2.1 “Network Information”
cordova-plugin-splashscreen 3.2.2 “Splashscreen”
cordova-plugin-statusbar 2.1.3 “StatusBar”
cordova-plugin-whitelist 1.2.2 “Whitelist”
cordova-plugin-zip 3.1.0 “cordova-plugin-zip”
ionic-plugin-keyboard 2.2.1 “Keyboard”
onesignal-cordova-plugin 2.0.10 “OneSignal Push Notifications”

4

Are you building your app with --prod flag?

I just installed and tested your app. The app launched in ~3-4 seconds.

5

In your config.xml

<preference name="SplashScreenDelay" value="7000"/>

app.component.ts

import { StatusBar, Splashscreen } from "ionic-native";
    
initializeApp() {
    this.platform.ready().then(() => {
          Splashscreen.hide();
          }
    }

while building your app use the following command

ionic build android --prod