Flutter: A Cross-Platform Development Framework

Introduction:

Flutter is a single codebase, free, and open-source framework that allows developers to build beautiful, natively-compiled applications for mobile (Android & iOS), web, and desktop (Windows & Linux). Developed by Google, Flutter was first published in 2017 and has since become a favorite among developers and users. In this blog post, I will explain what Flutter is, how it works, its benefits, and its pros & cons, along with some examples and market stats from 2020.

What is Flutter?

Flutter is a Software Development Kit (SDK) that comes with all the tools and libraries needed to build User Interfaces (UIs) using a single codebase. Flutter uses a declarative and reactive UI approach, meaning the state of your application is represented in functions and updates automatically when the value changes. Unlike other modern UI toolkits and frameworks, Flutter has a different paradigm; it does not require an OEM app or WebView to render interactive widgets. Instead, it uses Skia, its proprietary rendering engine, which renders widget views on the screen, giving clear control over the appearance.

Dart is the programming language used to write your application logic and UI code in Flutter. Dart is an object-oriented, class-defined language with a C-style syntax that can optionally be transcompiled into JavaScript. Flutter, in its latest stable release, has the capability to be transpiled to JavaScript via Dart for web support.

What Suits You the Best is Flutter?

Some of the advantages that Flutter provides developers and users are:

• Flutter is cross-platform, meaning that a single codebase leads to competent and reliable performance of the UI across all platforms. This minimizes development cost, development time, and even the effort required for maintenance and complexity.
• Hot reload & hot restart: Flutter supports a feature called Hot Reload, which can be considered similar to live change asynchronous methods in the development process, where developers can test and debug their apps without losing the app's entire current state. Hot reload makes code changes in just a few seconds to the running app, and hot restart also does this within 2–3 seconds by resetting/clearing everything from the current state.
• Rich and expressive UI: Flutter offers a wide collection of widgets that act as the basic building blocks for constructing beautiful app designs. The widgets are composable, adaptive, and customizable, and they can be combined with each other, making them suitable for different platforms or screen sizes. Flutter also supports animations, transitions, gestures, accessibility, and internationalization features to provide a better UI experience.
• Performance: Flutter delivers high performance in UI through its rendering engine and native code compilation features. Additionally, Flutter employs a layered architecture that abstracts the UI from platform design imperatives, optimizing UI production across every possible platform and device. Flutter even has stateful hot reload, which maintains the app's state and makes all-dependent refactoring faster than ever.

Cons of Flutter

Of course, Flutter has a couple of challenges and limitations too, such as:

• Dart programming: Flutter only uses Dart, meaning you need to develop your mobile application using this language. Another drawback is that the mental model for building UIs in other frameworks is different from how you do it with Flutter, so developers have to adjust their thinking and skills accordingly.
• No native features: You can't access some platform-dependent functionalities and services like camera, Bluetooth, GPS, etc., directly from Flutter. These features can only be accessed via plugins or platform channels, which enable developers to communicate with native code. This can create issues such as compatibility, performance, and security problems.
• Limited web and desktop support: For both, Flutter is still in beta stage, and its features aren't as fully developed as those for mobile devices. Certain functionalities cannot be implemented natively, such as downloading files, copying and pasting from one field, or creating right-click menus/browser extensions. Support for these features has taken away an important piece of interactivity that was previously available. Many important features are not being added, such as support for keyboard shortcuts and window resizing/drag & drop in C++/Dart ffi engines.

How is Flutter Used?

There are a number of types of applications that can be built using Flutter according to different needs and domains, such as:

• Social media: With Flutter, you can build interactive and beautiful UIs for social media apps like Instagram, TikTok, Facebook, Twitter, etc.
• E-commerce: You can recreate platforms like Alibaba, Flipkart, eBay, or even Amazon using Flutter to create responsive UI-based e-commerce applications.
• Education: Applications like Duolingo, Khan Academy, Coursera, and Udemy can be built using Flutter by making their UIs interesting for users with dashboards, graphics, or adaptive User Interfaces.
• Media (News/Entertainment): Flutter is ideal for creating media applications with immersive and dynamic UIs like Netflix, Spotify, YouTube, or Twitch.

Statistics on Flutter

Some stats to show the growth in popularity and adoption of Flutter:

• GitHub stars: Flutter has more than 150,000 stars on GitHub, making it one of the most starred repositories across all fields.
• Stack Overflow questions: Flutter is one of the most searched topics on Stack Overflow, with over 120,000 questions.
• Google Trends: Flutter search interest has been consistently rising, hitting its highest point around March 2021.
• App Downloads: Flutter has powered over 2 million apps downloaded from the Google Play Store, making it one of the most popular developer tools.
• User Satisfaction: Flutter has a rating of 4.6/5 based on over a thousand reviews.