diff --git a/packages/app/e2e/app.modular.e2e.js b/packages/app/e2e/app.modular.e2e.js
new file mode 100644
index 0000000000..b4b19fda60
--- /dev/null
+++ b/packages/app/e2e/app.modular.e2e.js
@@ -0,0 +1,321 @@
+/*
+ * Copyright (c) 2016-present Invertase Limited & Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this library except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+describe('modular', function () {
+  describe('firebase v8 compatibility', function () {
+    it('it should allow read the default app from native', function () {
+      // app is created in tests app before all hook
+      should.equal(firebase.app()._nativeInitialized, true);
+      should.equal(firebase.app().name, '[DEFAULT]');
+    });
+
+    it('it should create js apps for natively initialized apps', function () {
+      should.equal(firebase.app('secondaryFromNative')._nativeInitialized, true);
+      should.equal(firebase.app('secondaryFromNative').name, 'secondaryFromNative');
+    });
+
+    it('natively initialized apps should have options available in js', function () {
+      const platformAppConfig = FirebaseHelpers.app.config();
+      should.equal(firebase.app().options.apiKey, platformAppConfig.apiKey);
+      should.equal(firebase.app().options.appId, platformAppConfig.appId);
+      should.equal(firebase.app().options.databaseURL, platformAppConfig.databaseURL);
+      should.equal(firebase.app().options.messagingSenderId, platformAppConfig.messagingSenderId);
+      should.equal(firebase.app().options.projectId, platformAppConfig.projectId);
+      should.equal(firebase.app().options.storageBucket, platformAppConfig.storageBucket);
+    });
+
+    it('SDK_VERSION should return a string version', function () {
+      firebase.SDK_VERSION.should.be.a.String();
+    });
+
+    it('apps should provide an array of apps', function () {
+      should.equal(!!firebase.apps.length, true);
+      should.equal(firebase.apps.includes(firebase.app('[DEFAULT]')), true);
+      return Promise.resolve();
+    });
+
+    it('apps can get and set data collection', async function () {
+      firebase.app().automaticDataCollectionEnabled = false;
+      should.equal(firebase.app().automaticDataCollectionEnabled, false);
+    });
+
+    it('should allow setting of log level', function () {
+      firebase.setLogLevel('error');
+      firebase.setLogLevel('verbose');
+    });
+
+    it('should error if logLevel is invalid', function () {
+      try {
+        firebase.setLogLevel('silent');
+        throw new Error('did not throw on invalid loglevel');
+      } catch (e) {
+        e.message.should.containEql('LogLevel must be one of');
+      }
+    });
+
+    it('it should initialize dynamic apps', async function () {
+      const appCount = firebase.apps.length;
+      const name = `testscoreapp${FirebaseHelpers.id}`;
+      const platformAppConfig = FirebaseHelpers.app.config();
+      const newApp = await firebase.initializeApp(platformAppConfig, name);
+      newApp.name.should.equal(name);
+      newApp.toString().should.equal(name);
+      newApp.options.apiKey.should.equal(platformAppConfig.apiKey);
+      should.equal(firebase.apps.includes(firebase.app(name)), true);
+      should.equal(firebase.apps.length, appCount + 1);
+      return newApp.delete();
+    });
+
+    it('should error if dynamic app initialization values are incorrect', async function () {
+      const appCount = firebase.apps.length;
+      try {
+        await firebase.initializeApp({ appId: 'myid' }, 'myname');
+        throw new Error('Should have rejected incorrect initializeApp input');
+      } catch (e) {
+        e.message.should.equal("Missing or invalid FirebaseOptions property 'apiKey'.");
+        should.equal(firebase.apps.length, appCount);
+        should.equal(firebase.apps.includes('myname'), false);
+      }
+    });
+
+    it('should error if dynamic app initialization values are invalid', async function () {
+      // firebase-android-sdk will not complain on invalid initialization values, iOS throws
+      if (device.getPlatform() === 'android') {
+        return;
+      }
+
+      const appCount = firebase.apps.length;
+      try {
+        const firebaseConfig = {
+          apiKey: 'XXXXXXXXXXXXXXXXXXXXXXX',
+          authDomain: 'test-XXXXX.firebaseapp.com',
+          databaseURL: 'https://test-XXXXXX.firebaseio.com',
+          projectId: 'test-XXXXX',
+          storageBucket: 'tes-XXXXX.appspot.com',
+          messagingSenderId: 'XXXXXXXXXXXXX',
+          appId: '1:XXXXXXXXX',
+          app_name: 'TEST',
+        };
+        await firebase.initializeApp(firebaseConfig, 'myname');
+        throw new Error('Should have rejected incorrect initializeApp input');
+      } catch (e) {
+        e.code.should.containEql('app/unknown');
+        e.message.should.containEql('Configuration fails');
+        should.equal(firebase.apps.length, appCount);
+        should.equal(firebase.apps.includes('myname'), false);
+      }
+    });
+
+    it('apps can be deleted, but only once', async function () {
+      const name = `testscoreapp${FirebaseHelpers.id}`;
+      const platformAppConfig = FirebaseHelpers.app.config();
+      const newApp = await firebase.initializeApp(platformAppConfig, name);
+
+      newApp.name.should.equal(name);
+      newApp.toString().should.equal(name);
+      newApp.options.apiKey.should.equal(platformAppConfig.apiKey);
+
+      await newApp.delete();
+      try {
+        await newApp.delete();
+      } catch (e) {
+        e.message.should.equal(`Firebase App named '${name}' already deleted`);
+      }
+      try {
+        firebase.app(name);
+      } catch (e) {
+        e.message.should.equal(
+          `No Firebase App '${name}' has been created - call firebase.initializeApp()`,
+        );
+      }
+    });
+
+    it('prevents the default app from being deleted', async function () {
+      try {
+        await firebase.app().delete();
+      } catch (e) {
+        e.message.should.equal('Unable to delete the default native firebase app instance.');
+      }
+    });
+
+    it('extendApp should provide additional functionality', function () {
+      const extension = {};
+      firebase.app().extendApp({
+        extension,
+      });
+      firebase.app().extension.should.equal(extension);
+    });
+  });
+
+  describe('firebase', function () {
+    it('it should allow read the default app from native', function () {
+      const { getApp } = modular;
+
+      // app is created in tests app before all hook
+      should.equal(getApp()._nativeInitialized, true);
+      should.equal(getApp().name, '[DEFAULT]');
+    });
+
+    it('it should create js apps for natively initialized apps', function () {
+      const { getApp } = modular;
+
+      should.equal(getApp('secondaryFromNative')._nativeInitialized, true);
+      should.equal(getApp('secondaryFromNative').name, 'secondaryFromNative');
+    });
+
+    it('should allow setting of log level', function () {
+      const { setLogLevel } = modular;
+
+      setLogLevel('error');
+      setLogLevel('verbose');
+    });
+
+    it('should error if logLevel is invalid', function () {
+      const { setLogLevel } = modular;
+
+      try {
+        setLogLevel('silent');
+        throw new Error('did not throw on invalid loglevel');
+      } catch (e) {
+        e.message.should.containEql('LogLevel must be one of');
+      }
+    });
+
+    it('it should initialize dynamic apps', async function () {
+      const { initializeApp, getApps, getApp } = modular;
+
+      const appCount = firebase.apps.length;
+      const name = `testscoreapp${FirebaseHelpers.id}`;
+      const platformAppConfig = FirebaseHelpers.app.config();
+      const newApp = await initializeApp(platformAppConfig, name);
+      newApp.name.should.equal(name);
+      newApp.toString().should.equal(name);
+      newApp.options.apiKey.should.equal(platformAppConfig.apiKey);
+
+      const apps = getApps();
+
+      should.equal(apps.includes(getApp(name)), true);
+      should.equal(apps.length, appCount + 1);
+      return newApp.delete();
+    });
+
+    it('should error if dynamic app initialization values are incorrect', async function () {
+      const { initializeApp, getApps } = modular;
+
+      const appCount = getApps().length;
+      try {
+        await initializeApp({ appId: 'myid' }, 'myname');
+        throw new Error('Should have rejected incorrect initializeApp input');
+      } catch (e) {
+        e.message.should.equal("Missing or invalid FirebaseOptions property 'apiKey'.");
+        should.equal(getApps().length, appCount);
+        should.equal(getApps().includes('myname'), false);
+      }
+    });
+
+    it('should error if dynamic app initialization values are invalid', async function () {
+      const { initializeApp, getApps } = modular;
+
+      // firebase-android-sdk will not complain on invalid initialization values, iOS throws
+      if (device.getPlatform() === 'android') {
+        return;
+      }
+
+      const appCount = getApps().length;
+      try {
+        const firebaseConfig = {
+          apiKey: 'XXXXXXXXXXXXXXXXXXXXXXX',
+          authDomain: 'test-XXXXX.firebaseapp.com',
+          databaseURL: 'https://test-XXXXXX.firebaseio.com',
+          projectId: 'test-XXXXX',
+          storageBucket: 'tes-XXXXX.appspot.com',
+          messagingSenderId: 'XXXXXXXXXXXXX',
+          appId: '1:XXXXXXXXX',
+          app_name: 'TEST',
+        };
+        await initializeApp(firebaseConfig, 'myname');
+        throw new Error('Should have rejected incorrect initializeApp input');
+      } catch (e) {
+        e.code.should.containEql('app/unknown');
+        e.message.should.containEql('Configuration fails');
+        should.equal(firebase.apps.length, appCount);
+        should.equal(firebase.apps.includes('myname'), false);
+      }
+    });
+
+    it('apps can be deleted, but only once', async function () {
+      const { initializeApp, getApp, deleteApp } = modular;
+
+      const name = `testscoreapp${FirebaseHelpers.id}`;
+      const platformAppConfig = FirebaseHelpers.app.config();
+      const newApp = await initializeApp(platformAppConfig, name);
+
+      newApp.name.should.equal(name);
+      newApp.toString().should.equal(name);
+      newApp.options.apiKey.should.equal(platformAppConfig.apiKey);
+
+      await deleteApp(newApp);
+      try {
+        await deleteApp(newApp);
+        throw new Error('Should have rejected incorrect deleteApp');
+      } catch (e) {
+        e.message.should.equal(`Firebase App named '${name}' already deleted`);
+      }
+      try {
+        getApp(name);
+        throw new Error('Should have rejected incorrect getApp');
+      } catch (e) {
+        e.message.should.equal(
+          `No Firebase App '${name}' has been created - call firebase.initializeApp()`,
+        );
+      }
+    });
+
+    it('prevents the default app from being deleted', async function () {
+      const { getApp, deleteApp } = modular;
+
+      try {
+        await deleteApp(getApp());
+        throw new Error('Should have rejected incorrect deleteApp');
+      } catch (e) {
+        e.message.should.equal('Unable to delete the default native firebase app instance.');
+      }
+    });
+
+    it('registerVersion is not supported on react-native', async function () {
+      const { registerVersion } = modular;
+
+      try {
+        await registerVersion();
+        throw new Error('Should have rejected incorrect registerVersion');
+      } catch (e) {
+        e.message.should.equal('registerVersion is only supported on Web');
+      }
+    });
+
+    it('onLog is not supported on react-native', async function () {
+      const { onLog } = modular;
+
+      try {
+        await onLog(() => {}, {});
+        throw new Error('Should have rejected incorrect onLog');
+      } catch (e) {
+        e.message.should.equal('onLog is only supported on Web');
+      }
+    });
+  });
+});
diff --git a/packages/app/lib/index.js b/packages/app/lib/index.js
index 55fc1ca36b..fbb6697030 100644
--- a/packages/app/lib/index.js
+++ b/packages/app/lib/index.js
@@ -18,6 +18,7 @@
 import { getFirebaseRoot } from './internal/registry/namespace';
 
 export const firebase = getFirebaseRoot();
+export * from './modular/app';
 export { default as utils } from './utils';
 
 export default firebase;
diff --git a/packages/app/lib/internal/registry/app.js b/packages/app/lib/internal/registry/app.js
index fbf6b8bf79..9456630dd0 100644
--- a/packages/app/lib/internal/registry/app.js
+++ b/packages/app/lib/internal/registry/app.js
@@ -216,6 +216,10 @@ export function deleteApp(name, nativeInitialized) {
 
   const app = APP_REGISTRY[name];
 
+  if (app === undefined) {
+    throw new Error(`Firebase App named '${name}' already deleted`);
+  }
+
   const nativeModule = getAppModule();
 
   return nativeModule.deleteApp(name).then(() => {
diff --git a/packages/app/lib/modular/app.js b/packages/app/lib/modular/app.js
new file mode 100644
index 0000000000..7a3df0a0d7
--- /dev/null
+++ b/packages/app/lib/modular/app.js
@@ -0,0 +1,33 @@
+/* eslint-disable @typescript-eslint/no-unused-vars */
+import {
+  deleteApp as deleteAppCompat,
+  getApp,
+  getApps,
+  initializeApp,
+  setLogLevel,
+} from '../internal';
+
+/**
+ * Renders this app unusable and frees the resources of all associated services.
+ * @param app - FirebaseApp - The app to delete.
+ * @returns
+ */
+export function deleteApp(app) {
+  return deleteAppCompat(app.name, app._nativeInitialized);
+}
+
+/**
+ * Registers a library's name and version for platform logging purposes.
+ */
+export function registerVersion() {
+  throw new Error('registerVersion is only supported on Web');
+}
+
+/**
+ * Sets log handler for all Firebase SDKs.
+ */
+export function onLog(logCallback, options) {
+  throw new Error('onLog is only supported on Web');
+}
+
+export { getApps, initializeApp, getApp, setLogLevel };
diff --git a/tests/app.js b/tests/app.js
index 46551d8249..7acf0e6281 100644
--- a/tests/app.js
+++ b/tests/app.js
@@ -16,11 +16,11 @@
  */
 
 import '@react-native-firebase/analytics';
-import firebase from '@react-native-firebase/app';
-import NativeEventEmitter from '@react-native-firebase/app/lib/internal/RNFBNativeEventEmitter';
-import '@react-native-firebase/app/lib/utils';
+import firebase, * as modular from '@react-native-firebase/app';
 import '@react-native-firebase/app-check';
 import '@react-native-firebase/app-distribution';
+import NativeEventEmitter from '@react-native-firebase/app/lib/internal/RNFBNativeEventEmitter';
+import '@react-native-firebase/app/lib/utils';
 import '@react-native-firebase/auth';
 import '@react-native-firebase/crashlytics';
 import '@react-native-firebase/database';
@@ -41,6 +41,7 @@ import { AppRegistry, Button, NativeModules, Text, View } from 'react-native';
 jet.exposeContextProperty('NativeModules', NativeModules);
 jet.exposeContextProperty('NativeEventEmitter', NativeEventEmitter);
 jet.exposeContextProperty('module', firebase);
+jet.exposeContextProperty('modular', modular);
 
 firebase.database().useEmulator('localhost', 9000);
 firebase.auth().useEmulator('http://localhost:9099');
diff --git a/tests/e2e/globals.js b/tests/e2e/globals.js
index 3bab79dba5..070adfc271 100644
--- a/tests/e2e/globals.js
+++ b/tests/e2e/globals.js
@@ -59,4 +59,10 @@ Object.defineProperty(global, 'TestsAPI', {
   },
 });
 
+Object.defineProperty(global, 'modular', {
+  get() {
+    return jet.modular;
+  },
+});
+
 global.isCI = !!process.env.CI;