Adding Flipper to ReactNative

build.gradle

dependencies {
   ...
   debugImplementation("com.facebook.flipper:flipper:${FLIPPER_VERSION}") {
        exclude group:'com.facebook.yoga'
        exclude group:'com.facebook.flipper', module: 'fbjni'
        exclude group:'com.facebook.litho', module: 'litho-annotations'
    }
   ...

}

MainApplication.java

// Call this in MainApplication.onCreate(), just after Soloader line. 
private static void initialize(Context context) {
    if (BuildConfig.DEBUG) {
      try {
        /*
         We use reflection here to pick up the class that initializes Flipper,
        since Flipper library is not available in release mode
        */
        Class<?> aClass = Class.forName("com.facebook.flipper.ReactNativeFlipper");
        aClass.getMethod("initializeFlipper", Context.class).invoke(null, context);
      } catch (ClassNotFoundException e) {
        e.printStackTrace();
      } catch (NoSuchMethodException e) {
        e.printStackTrace();
      } catch (IllegalAccessException e) {
        e.printStackTrace();
      } catch (InvocationTargetException e) {
        e.printStackTrace();
      }
    }
  }

ReactNativeFlipper.java

/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * <p>This source code is licensed under the MIT license found in the LICENSE file in the root
 * directory of this source tree.
 */
package com.facebook.flipper;

import android.content.Context;
import com.facebook.flipper.android.AndroidFlipperClient;
import com.facebook.flipper.android.utils.FlipperUtils;
import com.facebook.flipper.core.FlipperClient;
import com.facebook.flipper.plugins.crashreporter.CrashReporterPlugin;
import com.facebook.flipper.plugins.databases.DatabasesFlipperPlugin;
import com.facebook.flipper.plugins.inspector.DescriptorMapping;
import com.facebook.flipper.plugins.inspector.InspectorFlipperPlugin;
import com.facebook.flipper.plugins.network.FlipperOkhttpInterceptor;
import com.facebook.flipper.plugins.network.NetworkFlipperPlugin;
import com.facebook.flipper.plugins.react.ReactFlipperPlugin;
import com.facebook.flipper.plugins.sharedpreferences.SharedPreferencesFlipperPlugin;
import com.facebook.react.BuildConfig;
import com.facebook.react.modules.network.NetworkingModule;
import okhttp3.OkHttpClient;

public class ReactNativeFlipper {
  public static final String CLASS_NAME = "com.facebook.flipper.ReactNativeFlipper";

  public static void initializeFlipper(Context context) {
    if (BuildConfig.DEBUG && FlipperUtils.shouldEnableFlipper(context)) {
      final FlipperClient client = AndroidFlipperClient.getInstance(context);

      client.addPlugin(new InspectorFlipperPlugin(context, DescriptorMapping.withDefaults()));
      client.addPlugin(new ReactFlipperPlugin());
      client.addPlugin(new DatabasesFlipperPlugin(context));
      client.addPlugin(new SharedPreferencesFlipperPlugin(context));
      client.addPlugin(CrashReporterPlugin.getInstance());

      NetworkFlipperPlugin networkFlipperPlugin = new NetworkFlipperPlugin();
      NetworkingModule.setCustomClientBuilder(
          new NetworkingModule.CustomClientBuilder() {
            @Override
            public void apply(OkHttpClient.Builder builder) {
              builder.addNetworkInterceptor(new FlipperOkhttpInterceptor(networkFlipperPlugin));
            }
          });
      client.addPlugin(networkFlipperPlugin);

      client.start();
    }
  }
}