Ionic You need to use a different package name because “io.ionic.starter” already exists in Google Play

If you are using Ionic + Android Studio to publish an app and run into this error on upload, “You need to use a different package name because “io.ionic.starter” already exists in Google Play”, do this.

Check build.gradle (Module:android.app) file in Gradle Scripts

apply plugin: 'com.android.application'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.myexampleapp.unique"
        minSdkVersion 21
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }

Change the applicationId to a unique ID. The nomenclature is typically “appname.yoursite.com” but backward, like “com.yoursite.appname”.

Rebuild the file and publish.

Credit: @Rich Tillis