Flutter App Development Box-set: Let’s Create a Highly Secure Flutter App

Ryan Miller
5 min readMay 4, 2022


Flutter App

We’re running over Flutter’s alimentary features and benefits to understand what a full-fledged Flutter App is capable of and how to secure it!

As we run through the blog, the foreword, features and benefits converge simultaneously. It all accumulates to make the best out of Flutter App Development.

Flutter is Google’s cross-platform app development framework for building highly effective UI’s and natively compiled mobile applications for mobile, web, desktop and embedded devices from a single codebase.

  • It is compatible with the Visual Studio Code, IntelliJ Idea, and Android Studio.
  • It enlivens beautiful designs, smoother animations, uplifts app performance, does more in fewer lines of code, intermittent debugging, state full hot reload, produces customizable design, and enables using Google Firebase.
  • Flutter saves cost as a single codebase works across platforms, thus saving efforts, time and cost.
  • You do not have to compromise on app performance or speed with the Flutter framework. It eases gaming app development.
  • It enables reusing the same code on multiple platforms and eases the hot/reloading feature.
  • It has widget catalogues, IDE’s, tools that provide adequate visual assistance and debugging the code. Flutter comes with widget catalogues, IDE’s that provide visual ‘assistance’ and debugging the code.
  • It has a rendering engine, a simple platform-specific logic. Flutter owes fast development, expressive and flexible user interface, increasingly fast rendering, customizable widgets, expressive and flexible designs, Stateful Hot reload, scrolling, navigation, icons and fonts, fixes bugs faster, and rich motion API’s.
  • Flutter compiles to native ARM machine code using DART’s native compilers; access platform APIs and services and use the GPU.
  • Flutter permits changing code and debugs from where you left off.
  • Flutter moves the widgets rendering, animations, gestures into the framework that controls every pixel on the screen.
  • Flutter offers reactive-style views without using a JavaScript bridge.
  • Flutter-Dart makes use of Ahead-of-time or AOT compilation and Just-In-Time or JIT compilation.
  • Flutter Widgets moderates according to requirements.
  • Flutter is versatile because it offers native performance across platforms, offers expressive and beautiful UI features, drives business agility within the given time frame.
  • (1) Google Ads, (2) eBay, (3) Alibaba Group, (4) Square, (5) GROUPON, (6) New York Times, (7) Capital One, (8) BMW, Xianyu by Alibaba, (9) Postmuse — Instagram photo editing app, (10) Hamilton, (11) Lunching, (12) Pairing, (13) Watermaniac, and (14) Cryptograph are some examples of apps built using Flutter Framework.
  • The average Flutter app development cost for an app with medium complexity comes around $80 000 to $150 000.

Why is Flutter App Development preferable?

To create fast, beautiful, interactive applications that are scalable. Flutter is not restrictive of the size of the enterprise or platform capability. It is innovative and has extensive community support. Flutter Apps completes faster due to faster development lifecycle coupled with reduced time for quality assurance.

How can you secure your Flutter mobile app?

  • Stay Up-to-date: Keep your Flutter SDK updated with security fixes and patches to avert any vulnerabilities.
  • Obfuscate Code: Encrypt or obfuscate Flutter code to avert overexposing the strings, methods, class names and API. Such data can be either in original form or in plain text. It looks like this:
  • Rename Obfuscation
  • Secure API Keys: Restrict API access to API keys/ API strings. Go to console, select API and services, and restrict any services, depending on the importance. If you’re using Google APIs or Firebase, you may want only specific services to use it. And for all services that do not have server-side restrictions, move the integrations to the backend and expose the methods via RESTful APIs. Also, you can encrypt/decrypt API keys on runtime.
    Also, do not track API keys on your repository for open-source projects. Enforce the use of environment configuration files instead. Issue the environment configuration files to your team using Lastpass or a similar password manager. And do not share API keys, tokens, and any sensitive data in plain-text on your communication tools like Slack or Discord.
  • Avoid using Firebase Remote Config: Firebase remote config allows making changes without publishing a new build. This service should not store sensitive data.
  • Restrict Network Traffic: Explicitly white-list your domain. Also, you can implement certificate pinning for your apps to restrict the secure connection to particular certificates. It ensures trust between your servers and apps.

Photo Credits: TLS Certificate Pinning 101 — Nettitude Labs

  • Limit Permissions: Access hardware or native API of your users’ devices if the plugin has dubious permission requests.
  • Secure User Data: Personally identifiable data might be required but use Flutter secure storage package that uses Keystore for Android and Keychains for iOS or auth tokens for storing them.

Android Keystore Architecture

  • Integrate Local Authentication: The flutter plugin for Android and iOS devices allows local authentication via fingerprint, touch ID, faceID, passcode, PIN, or pattern.
  • Secure Your Developer Identity: Encrypt Google Service Account, Keystore.properties, Keystore and any such accounts that have the potential to expose your developer identity when tracking them in a repository. To implement this, create a directory and use GPG to encrypt it and decrypt it later.
  • Secure Your CI Infrastructure: Keep your virtual machines and workflows updated, even if your CI infrastructure is self-hosted or using services like GitHub actions. Also, do not commit API keys or related sensitive data in your code. Instead, you can add them to the settings of your project.
  • Access Board: Create an ‘access board’ so that your team can create tickets for each request made to access services. It allows them to practice transparency and make requests.
  • Password Manager: Use a password manager like LastPass to secure the process of sharing credentials.

In Conclusion:

If people can’t remember what you say, it is as if you never said it. The one thing we need you to recall ‘even if you forget the rest is — “Flutter is a cross-platform app development framework that provides the best user experience.” It is customizable, performant, and easy to code. We hope that the tips that we’ve shared here help you understand different areas to improve the security and privacy of Flutter apps. Visit us for more! https://www.itfirms.co

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Originally published at https://www.itfirms.co on May 4, 2022.