Local development builds fail with targetSdkVersion 28 because starting from Android 9, clearText support is disabled (https://developer.android.com/training/articles/security-config#CleartextTrafficPermitted). It is not mentioned anywhere in the docs, maybe we could include it somewhere?

To make sure the app is able to communicate with metro bundler, you need to add android:usesCleartextTraffic="true" to your AndroidManifest.xml file so it should finally look something like:

 <application
      android:name=".MainApplication"
      //...
      android:icon="@mipmap/ic_launcher"
	  android:usesCleartextTraffic="true" <-- add this
    // ....
>

If you don't add this, your app would build and launch but would fail with the following screen: