In the mobile app development space, use of Flutter for mobile app development is a hot topic. Many of our customers started inquiring if they should go with Flutter over traditional methods, what are the benefits involved etc. This article briefs our insights on using flutter for mobile app development.

What is flutter?

Flutter is Google’s UI toolkit for building beautiful, natively compiled applications for mobile, web, and desktop from a single codebase. It offers fast development, expressive and flexible UI and Native Performance. It is used to develop applications for Android and iOS, as well as being the primary method of creating applications for Google Fuchsia. It is intended to make cross-platform app development easier than ever before. Since its first release in 2018, Flutter is getting a lot of attention from mobile app developers and businesses from all over the world. The completely open-source SDK is based on the Dart programming language, which is new, but easy to learn and get started with. From faster development and simultaneous app updates to save a lot of time and easy maintenance, Flutter for mobile app development has a lot of advantages. 

Like any new technology framework flutter also comes with a set of pros and cons. Flutter sure eases the app development process and based on our observance, crash rates are very low in flutter apps. However, the biggest disadvantage we see in flutter is its developer community size. But, given time, we can expect the community to grow stronger to drive more innovations to the framework. It is a great framework for some projects, but it is not yet the right choice for a varied set of applications and use cases. As all cross-platform technologies, it also has limitations. 

Amazing benefits packaged in a single framework,

Flutter saves lots of app development time, ideally 40% faster than development with native SDKs. The main attraction of Flutter is its large collection of widgets which can be customized and delivers more than the performance we expect, delivering performance that feels like a native. The Hot reload feature of Flutter enables developers to identify the bugs faster and fix them in real-time. When it comes to UI, Flutter doesn’t use the platform UI. It renders everything by itself and enables developers to build apps with really good UX. 

Flutter UI rendering and limitations

Flutter is a lot different from the other frameworks available today. A flutter app is composed of widgets that are rendered to a Skia canvas, which is displayed by the platform and sends events back as required. This model can deliver high-performance outcomes. Flutter’s own UI rendering feature gives the developer some limitations. For example say you need to implement a video player in your application. You can do it with the widgets of a video player in Flutter but they look different than the native one, especially on iOS. Another example – you must be familiar with the “remember this email or password” prompt above keyboard? This feature is not supported in Flutter. To solve this problem, developers need to write native view for a text field in iOS and embed it in Flutter. A Flutter app uses the GPU for most of the work and updates the UI at 60 FPS, which provides a smooth experience to its users.

No Standard or Universally-accepted Architectural Approach 

On Android SDKs developers normally use Clean Architecture and MVP (model-view-presenter) while on iOS, they use MVC, MVVM (model-view-ViewModel) or Viper. In both platforms, there is a clear well known architectural patterns for a large project. Unfortunately for Flutter, there is no ‘standard’ or ‘universally-accepted’ architectural approach. If you are a developer working on a very large project, then it is advised to have a clear idea of how to structure it in order to make the app more scalable and easily maintainable as the app grows in size and complexity.

Dealing with the Large file size 

Minimizing the size of an app is a crucial aspect for developers. Because users have limited storage on their phones, it makes sense for the developers to build an app that won’t make them delete it in favor of precious photos or music. A few practices to minimize the app size are avoiding animations, bringing the number of libraries and packages to a minimum, and compressing the images. However, using Flutter for mobile app development results in having an app with an enormous file size. For example, the release file size of the Hello World app using Flutter reached 6.7MB, whereas the same app developed in Java and Kotlin was 539KB and 550KB respectively. So, this is a piece that needs considerable contributions from the community, to enable app development with a low footprint. 

Lack of third-party libraries, plugins and UI components

When it comes to automating software development that allows programmers to relieve the need to code everything from scratch, third-party libraries and packages play a crucial role. The third-party libraries are mainly open-source, easily available, and pre-tested. Flutter for mobile app development, like any new technology, doesn’t have a large number of libraries. While Flutter’s official resource of free packages gets better with new tools and features, there will be a significant waiting period. Although Flutter has a decent list of good looking UI components and other plugins, it’s not as rich as plugins you can find for React Native and even Xamarin. Moreover, the choices are very limited and many plugins are old and not maintained. Some of them won’t even work anymore with the current version. Apart from that, some UI components are only available for either iOS or Android, but not both.

So, Should you go for Flutter?

If you intend to launch your app as Android or iOS only, and if it needs many interactions with the OS, then we recommend you to go for native app development. Otherwise, it’s good to go with Flutter, given the smooth experience and performance it delivers.

I’ve also written a detailed tutorial article explaining step by step, how to implement navigation between widgets and screens in Flutter and pass data between Widgets/Screens.