Firebase and Google Services in Mobile Development: What They Are, Services, and How to Use

What is Firebase?

Firebase is a Backend-as-a-Service (BaaS) platform that provides ready-made tools for application development. Firebase saves developers from having to build server infrastructure from scratch — analytics, databases, authentication, push notifications and much more are available out of the box via the SDK.

Google acquired Firebase in 2014 for $100 million and integrated it with Google Cloud Platform. Firebase offers over 20 products that can be combined depending on project needs. Most services have a generous free tier (Spark Plan), and a pay-as-you-go paid plan (Blaze Plan) is available for growth.

Integrating Firebase starts with creating a project in the Firebase Console and adding a configuration file (GoogleService-Info.plist for iOS, google-services.json for Android). Firebase supports iOS, Android, Flutter, React Native, Unity and web applications, making it a universal solution for any platform.

Analytics and Monitoring: Analytics, Crashlytics, Performance

Firebase Analytics is a free analytics tool that collects data about user behavior. Firebase Analytics is the core of the entire platform — analytics data is used by all other Firebase services for targeting and personalization.

Crashlytics — real-time crash reporting

Firebase Crashlytics is the most popular tool for tracking app crashes. Crashlytics automatically collects stack traces, logs, and device data whenever an app crashes. Reports are grouped by error type, allowing you to quickly identify the most critical issues.

Crashlytics supports custom logs, keys, and non-fatal exceptions. Non-fatal exceptions allow you to track handled errors without crashing the app — for example, a failed API request or an exception in business logic.

Firebase Performance is a tool for monitoring app performance. Performance tracks startup time, network latency, screen rendering, and HTTP requests. It identifies bottlenecks that slow down the app and degrade the user experience.

Integrating Firebase Analytics with Crashlytics provides a unique ability to see not only what crashed, but also what user actions preceded the crash. IT Sectr uses this combination for rapid bug diagnosis in production — time from detection to fix is reduced by 3–4 times.

Databases: Firestore, Realtime Database, Storage

Firebase offers two NoSQL databases and cloud storage for files. The choice between Firestore and Realtime Database depends on the use case — both databases sync data in real time but have different architectures.

Firestore vs Realtime Database

Cloud Storage is a file storage (images, video, audio). Firebase Storage automatically scales to petabytes and provides reliable upload with resume on connection interruption. It integrates with Firebase Auth for secure access.

Firestore is recommended for new projects due to its flexible queries and scalability. Realtime Database remains a good choice for simple chats and games with small amounts of data. IT Sectr typically uses Firestore as the primary database and Realtime Database only for real-time collaborations.

Authentication: Firebase Auth, Google Sign-In

Firebase Authentication is a ready-made solution for user authentication. Firebase Auth supports email/password, Google, Apple, Facebook, Twitter, GitHub, phone auth and anonymous sign-in. The entire authentication process is implemented on the client side via the SDK.

Google Sign-In is one of the most popular authentication providers. Integrating Google Sign-In takes 15–30 minutes through the Firebase Console and requires no backend development. Users sign in with one click using their Google account.

Firebase Auth also provides backend functions via the Admin SDK. You can create users, update profiles, manage sessions, and verify ID tokens on the server. Integration with Cloud Functions allows creating custom authentication scenarios.

Security Rules — Firebase's security mechanism for databases and storage. Access rules are described declaratively and are checked on every request. For example: allow reading a document only if userId equals the currently authenticated user.

Example of a simple Security Rule for Firestore:

rules_version = '2';
service cloud.firestore {
  match /databases/{database}/documents {
    match /users/{userId} {
      allow read, write: if request.auth.uid == userId;
    }
    match /posts/{postId} {
      allow read: if true;
      allow write: if request.auth.uid == resource.data.authorId;
    }
  }
}

Marketing: Cloud Messaging, Remote Config, Dynamic Links, A/B Testing

Firebase Cloud Messaging (FCM) is a service for sending push notifications. FCM handles up to 500 billion messages daily and supports iOS, Android and Web. Messages are divided into notification messages (automatic display) and data messages (in-app processing).

Remote Config — flexible management of app parameters

Firebase Remote Config allows you to change app behavior without publishing a new version. Remote Config is used for A/B testing, feature toggles, UI customization and dynamic parameter changes (e.g., ad frequency, paywall text).

Firebase A/B Testing is a tool for running experiments. Create two versions of the app with different parameters and measure the impact on metrics (conversion, retention, revenue). Tests automatically calculate statistical significance and determine the winner.

Firebase Dynamic Links are smart links that take users to the right place in the app. Dynamic Links work even if the app is not installed — in this case they go to the store page, and after installation restore context and redirect to the target screen.

IT Sectr uses the Remote Config + A/B Testing combination to optimize all key scenarios: from the welcome screen to the payment flow. Remote Config parameters can be changed in real time via the Firebase Console — this provides flexibility not available with traditional release cycles.

Testing: Test Lab, App Distribution

Firebase Test Lab is a cloud solution for automated app testing. Test Lab runs your tests on real Google devices in various configurations (different OS versions, screen resolutions, languages). Supports Espresso (Android), XCUITest (iOS) and Robo tests.

Firebase App Distribution is a platform for distributing beta versions of apps. App Distribution replaces TestFlight for Android and complements it for iOS. You can upload APK/AAB and get feedback from testers through Crashlytics integration.

The combination of Test Lab and App Distribution ensures quality at all stages of development: from automated tests on real devices to beta testing with real users. Integration with CI/CD (GitHub Actions, Bitrise) makes the process fully automatic.

Firebase Services Overview