What is Flutter: A Comprehensive Guide

In the modern smartphone-infested world, mobile apps reign supreme. People all over the world use them for work, entertainment, shopping, etc. Astute entrepreneurs rely on savvy app developers to find new ways of connecting with consumers and boost revenues at the same time.  But today the pace of technological development is so rapid that it is hard even for IT experts to keep the track of all novelties which crop up almost every week. That’s why there is no wonder that the question “What is Flutter?” is far from being rhetorical. In this article, we will review flutter meaning and show the benefits of using it.

A Concise Flutter Review

Talking about flutter definition, you should know that the first version of Flutter, which is known as “Sky”, appeared five years ago. For Google, like for its creator, it took three more years to get this open-source UI framework into shape and prepare its stable version for release, which was in December 2018. Being limited by using only on Android-powered devices, Flutter was gradually turned into a cross-platform tool that can be employed for building applications for iOS, Linux, Windows, and other operating systems from one codebase. Currently, Flutter is mostly focused on mobile application development. However, it is also possible to create Flutter desktop applications. Such sophistication let Flutter get a place in the top ten of the most utilized frameworks in 2020.

most used frameworks statistics


Google keeps improving and augmenting its product, so Flutter’s latest 1.17.0 version released in 2020 provides advanced performance on Apple gadgets as well as fresh Material widgets and novel network tracking.  According to the Google flutter review, there are two main Flutter components. The first is a Software Development Kit (SDK) that includes a set of tools for building apps including those that convert its code into native Android and iOS codes. The second is a UI widget-based library (aka framework). Its elements (buttons, sliders, text inputs, etc.) will let you tailor your future app to your unique needs. The flutter programming language is Dart. Dart is primarily honed for front-end development. It requires a little fine-tuning to learn how to work with it in case you have good skills in Java or C++ programming. All the elements are combined to form a unique architecture.


The structure of the Flutter framework significantly conditions the way it operates.

How Does Flutter Work: Nuts and Bolts

Having accumulated substantial experience of working with apps (both mobile and web), the experts of Deventor find that Flutter considerably streamlines the development process. It is due to native compilation to the ARM processor, foolproof rendering, and a whole bunch of integrated tools and widgets. The latter is used to define particular elements of the app – structural (menus, buttons), layout (padding), stylistic (fonts, colors), etc. Moreover, developers can create their own widgets if the available ones seem inadequate or deficient. Flutter functions look in the following way. Instead of immediately compiling to any native app, Flutter launches applications together with the engine. Consequently, all generated files replace native app elements with respective Flutter SDK components. Flutter apps’ performance is quite satisfying with 60 frames per second on most devices (and if it supports Flutter, the rendering speed increases up to 120 FPS), but it can negatively influence the size of the apps made with Flutter.  Flutter doesn’t need a JavaScript bridge for connection with the platform. The connection carries out directly via Dart which is compiled ahead of time (AOT) into the code used for native platforms. This way, the app’s start time is greatly reduced. Other benefits that come with Dart include refreshing the tree view for each new frame, employing generational garbage collection, the presence of a “tree shaking” compiler, and a large repository of software tools that can be leveraged to augment the apps’ capabilities. In addition to all of these, Flutter features a godsend – the Hot Reload function. Pressing this button you can immediately display all code alterations in emulators, simulators, and gadgets. The work of the app proceeds from the place where it was before the button of the code update was pressed. Like any other app-building tool, Flutter has not only appealing advantages but unpleasant drawbacks as well.

Flutter App Development: Pros

The above-mentioned features of Flutter define the benefits this tool brings to developers and users.

Saving Both Money and Time

Being a cross-platform tool, Flutter excludes the necessity of building two apps that will fit the two major operating systems (Android and iOS). Instead, you build one universal app with a single UI, which can save (according to the estimations of Deventor’s experts) 30% of your expenses on average. Surely, the time of Flutter mobile development is shorter as well – making one item instead of two is always faster. For the same reason, testing takes less time as well. As a result, in 2-3 months, you can get a completed product that is a very solid time-to-market indicator.

High Development Speed

The tremendous advantage of Flutter coding over other frameworks is the hot reload feature that provides faster delivery of new elements. Due to it, the Flutter dev can instantly observe all code changes without restarting the app every time the alterations are introduced. All errors and bugs are dealt with while the app is running, and even if you have to reload it, this maneuver is accomplished in no time.

No Compatibility Issues

All Flutter reviews emphasize that the number of compatibility problems is almost absent that is achieved due to two characteristics of the framework. The first is the flutter language used: Dart compiles directly into native code. The second is the inbuilt widgets Flutter has. Such peculiarity excludes the need to have access to OEM that significantly reduces interaction between the app and the framework (where all incompatibilities come from).


Growing Popularity and Community

Being an open-source framework, Flutter is enjoyed by a wide audience of users who can always give a helping hand to each other if it’s needed. Google support means relevant structured documentation and the abundance of real-case implementations, so friendly help of the community is just an additional benefit. Moreover, Google’s involvement stimulates the Flutter team to keep the framework with its widgets vibrant and constantly developing, which is a real challenge that isn’t always adequately solved by older technologies (for instance, React Native).

Flutter App Development: Cons

Despite the evident benefits, any Flutter review would be incomplete if we don’t mention the limitations the tool has.


Flutter has all the shortcomings which can be exposed in the novel products. Lack of stability, flaws in development, absence of some functions, tools, and libraries are nuisance features of all immature projects. Specialists in Flutter with adequate experience are still hard to find, and assembling a team of them will surely take some time and effort.

Excessive File Weight

Modern gadgets’ memory is often overcrowded with games, music, videos, so finding room for another app may be a problem. Flutter apps don’t meet users’ expectations in this aspect as they weigh about 4 MB, which is too much in comparison to the average volume of 500KB that native apps have.

Flawed Password Manager Support

With Flutter apps, implementing password extraction from third-party or integrated password managers is a problem when working with autocomplete input fields. After all, non-native widgets aren’t always a blessing.

Inadequate Support for iOS Features

Because of Apple’s lukewarm attitude to the products of their competitors, many iOS special features (Audio Description, Guided Access, VoiceOver, and others) aren’t supported by Flutter apps. Photos are also inadequately handled on Apple devices as the app deletes all EXIF files which leads to the wrong orientation of the picture and absence of location- and date-related information. Moreover, a new version of iOS or even Android needs updating of all Flutter widgets by the vendor, which is also inconvenient.  As you can conclude from the nature of the limitations, they are rather growing pains than serious deficiencies. Weighing all pros and cons, you must always remember that any native app-building tool has an edge over platform-independent technologies in productivity, but among cross-platform frameworks, Flutter has no equal in performance and visualization. So there is no wonder that its usage is gaining momentum among software experts.



Considering its undeniable advantages, many blue-chip companies leverage Flutter to create a commercial app.

The Examples of Apps Built with Flutter

So, what is flutter used for? Flutter turned out to be a viable option for building apps for a whole gamut of industries: banking and fintech, suppliers and franchisees, online stores and retail ventures (that rely on catalogs and loyalty programs), and large businesses. The latter starts the Flutter mobile app that will help them handle the organization of workflow, courier management, contact center administration, etc. Examples of big-time companies that leverage Flutter include Yandex, Uber, Airbnb, eBay, BMW, and other names. The most popular Flutter app are:

  • Google Ads. It is natural that the company which released Flutter uses it. In addition to launching dozens of apps built with Flutter, this venture has totally updated its Google ads platform. Its list of features has been significantly extended by real-time alerts and in-depth details of the campaign.
  • Alibaba. Having earned a high reputation as an e-commerce site, it launched a mobile app. Flutter developers played their part in its upgrading, which led to global transactions expanding and customer satisfaction boosting.
  • Birch Finance. Honed for credit card management, this fintech app optimizes analyzing and tracking bonus points earned by clients and helps to use them more efficiently.
  • Hamilton Musical. Being an official app of the popular Broadway performance, it is used by the show producers to keep its fans updated on the information and the latest news and also to upload videos.
  • Reflectly. This lifestyle Flutter-powered app is something like a digital diary that also gives users advice on their personal-life decisions by offering them some questions every day and providing insights as to their moods and feelings.

How to Test Flutter Apps

There exist three main groups of automated Flutter tests. Among them are:

  • Integration testing
  • Unit testing
  • Widget testing

An important thing to know is that unit tests test one feature, method, or class. Meanwhile, widget tests test one widget. Widget tests are also named component tests. The majority of Flutter tests, traceable by code coverage, are made up of widget tests and unit tests. The last point is integration tests. They test the whole application or its considerable part encompassing all the crucial use cases.

Why Choose Flutter for Your Next Project

In fact, there exist things that have a significant value for the business. Among them, we define the following: stability of the platform, platform performance, successful support guarantee as well as technologies and products improvement. Issues and disadvantages in any of these aspects can lead to the risks comprising indirect and direct financial losses.

Flutter allows reducing the risks for your business thanks to the points such as:

  • The greatest in class (cross-platform) performance and resource consumption thanks to the compilation of native code and high-performance rendering engine,
  • Flutter programming provides better productivity. Developers work more efficiently thanks to the fact that Flutter is primarily designed for quicker code writing,
  • Accelerated time to market,
  • The cost of app development is low.

Flutter vs React Native vs Xamarin: The Best Choice

To compare Flutter vs Xamarin and React Native vs Flutter and help you make an ultimate choice, we will answer the question: will Flutter replace React Native and Xamarin?

Short answer: No.

Long answer: Taking into account Flutter’s rapid growth in just several years and Google’s continuous support, Flutter is certainly here to stay. It attracts more and more developers by its capabilities, performance, and ease of use. Just give it try and become avid fans.

However, we’re sure that Flutter is a worthy rival to the older and more mature frameworks and that the market share of Flutter mobile apps — and as we have already mentioned, also web and desktop solutions — will continue growing.

We also recommend reading: How to Make a Progressive Web App: Tutorial

How Long Can We Expect Flutter to Be Around for?

It’s clear that nobody wants to be the person adopting a completely new language and framework that may fizzle out only after some months. So, there is no wonder that there exist quite valid concerns about the Flutter technology longevity. The main cause of why Flutter has fans and such popularity is the support of Google. Without any doubt, great events like Flutter Interact, high-quality learning materials as Widget of the Week are supported by Google’s finances. But what would be if Google stop its support and funding?


Cross-platform apps are a godsend for entrepreneurs who want to establish a rapport channel with a wide circle of customers quickly and without incurring major costs. Flutter is a robust framework that can be incredibly useful in building such an app that will definitely provide financial prosperity for your company. Flutter app can add value to any business you are engaged in. And in certain circumstances, it fits the best.

If you want to have an instant app or one that will be connected with any gadget via Bluetooth, Flutter is what you need. It also suits perfectly for building an MVP to show its benefits to potential investors.  No matter which app you plan to launch, you must ensure that it has excellent performance and superb UI design. And at this point, Deventor can help you. Our experts will produce a high-quality Flutter app at an affordable price – contact us with your app idea to get a project estimate.

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