What You Will Learn

In this article, we're going to break down a rather interesting type of application: the universal application, or cross-platform application. We'll touch upon some various methods of developing them, the tools available to help you build them, and weigh their benefits from both a user and developer's perspective. Let's get started!

Today, software applications have become commonplace in virtually every industry out there. From transportation, education, and healthcare to food and beverage—you name it, software applications are everywhere!

And with this growing demand for software application development, there's an increasing need to build them faster and more efficiently. This need has driven the evolution of app development in the past decade.

In the early days, developers swore by the waterfall model, then the monolithic structure, and now, microservices and AI (Artificial Intelligence) are dominating the market. As technology advances, we push the boundaries of what can be accomplished, and new applications are being created to overcome the shortcomings of their predecessors.

Enter: Universal Applications!

If you've ever built an app, you probably understand the frustrations that come with creating individual app versions specifically for both the Google Play and Apple Play stores. But what if you could create a single version that was compatible across all platforms? Not only would it save you time and money—it could help you get your app to market before any of your competitors, too!

An iPhone with a display of the apps they have on their homepage.

Introduction To Universal Applications

One of the primary goals of any software market or business is to extend their reach to the most users possible, and creating cross-platform applications is one recommended way to achieve this goal. After all, the more platforms that you can publish your app on, the more users you're capable of reaching!

If you want to reach the most users possible in a short period of time, consider building a universal application that will allow you to 'write once, run anywhere'.

Universal applications have a single code base, and they use that codebase to run applications on different platforms without duplicating the code or building again. This makes the codebase both easily maintainable and reusable.

Different Tools to Build Universal Apps

Engineering platforms have a lot to offer, and there are an abundance of tools, IDEs, and platforms to choose from when building universal apps. Here are a few pointers to keep in mind as you assess which tool you'd like to use:

  • Speed: How fast is the development?
  • Support: Will the platform support the feature that we want to implement?
  • Cost: How cost-effective is the tool?
  • Risk: Are there any risks involved with the usage of the tool?

Any tool that checks most, if not all, of the boxes above will be your best bet, but we've curated a list of four of the most commonly used tools below to help you get started.

1. React Native: Most Loved by Developers!

Originally developed by Facebook in 2014, React Native was created to help Facebook developers take React, a framework for helping developers build single-page apps the company developed in-house, and allow them to use these same skills to build native mobile apps for iOS and Android. At the time, it created quite a stir in the app development world, and according to this survey by Statista, React Native was the most widely used tool developers used to build universal apps in 2020.

Here's a flow chart to help you visualize the universal application building process using React Native (see Fig. 1, below).

A flow chart that shows how to use React Native to build universal applications.
Fig. 1: React Native Development Flow

In simple terms, React Native is a cross-platform technology that uses open-source JavaScript to bring the task of writing for two very different operating systems (like Android and iOS) together under one roof.

Using React Native in this way means:

  • You don't have to write quite as much JavaScript, CSS, and HTML code
  • React Native runs your application in the host platform's JavaScript engine, thereby avoiding the need to compile down to native code
  • You get all of the benefits of native performance without needing to write any OS-specific code

It's not without limitations though! The React Native framework is ideal for building simple apps, but developers run into problems when they start dealing with more complex mobile app development. To bypass these challenges, developers often need to create a bridge to export native elements from a specific platform to JavaScript.

2. Xamarin: Best Suited for .NET Developers

Xamarin is an open-source mobile app platform that allows you to build apps for Windows, iOS, and Android platforms using a single .NET codebase. And the fact that it's both open-sourced and owned by Microsoft makes it a time-tested and trustworthy solution for cross-platform app development!

Since Xamarin relies on C# language, this platform is best suited for .NET developers. Here's a road map highlighting how universal apps are built using React Native (see Fig. 2, below).

A mobile app development flowchart using Xamarin
Fig. 2: Xamarin Development Flow (Source)

Xamarin helps you expedite native mobile app development with up to 85% of code reusability across various platforms. As you can see, we have the OS kernel on which the Mono runtime sits, which in turn has .NET APIs and C# code on top of it. Xamarin allows for managed code to invoke native APIs via bindings.

In Android, Managed Callable Wrappers (MCWs) are used when managed code needs to invoke Android code, and Android Callable Wrappers (ACWs) are used when Android runtime (ART) needs to invoke managed code.

Xamarin could be a better choice for .NET developers. The C# codebase is compiled to native components of the Android and iOS platforms. Thus, speed and performance are ensured across platforms. Plus, it gives you access to the cloud testing facility of Visual Studio App Centre.

3. Flutter: Multiplatform SDK by Google

Flutter is a software development kit introduced by Google in 2017, and it's relatively new to the universal app development game in comparison to React Native (2014) and Xamarin (2011). Flutter uses an in-house language developed by Google called Dart, which can be easily adapted by Java or Javascript developers. Flutter allows you to incorporate widgets like navigation, galleries, dropdowns, etc. according to your needs providing a full native performance.

Here's what a typical universal Flutter app architecture looks like (see Fig. 3, below):

A diagram showing the framework for Flutter utilizing Dart and C/C++.
Fig. 3: Flutter Architecture (Source)

As you can see, the Dart framework exposes the application to items like widgets, gestures, and animation. The core is the Engine—typically written in C/C++, it provides a low-level implementation of Flutter's core APIs. At the bottom is the Embedder, which coordinates with the underlying OS for rendering services. The embedder can integrate Flutter code into an existing application as a module, or the code may be the entire content of the application.

According to this survey by VentureBeat, Flutter is the fastest growing tool for universal app development. It could be the best solution for organizations looking for rapid development along with high performance, however, it would require the developers to be skilled enough to adapt well to the complexity of the tool.

Why Are Universal Apps the Future of App Development?

We believe that these apps could be the next big thing, but let's see what makes them futuristic:

  • Reaching out to the audience: Since the applications are available across multiple platforms, they cater to a more extensive set of users. This increases the potential revenue and user base.
  • Hassle-free cloud integration: Cloud integration is one of the main reasons businesses switch to universal app development. By integrating with cloud services, they can build a functional and scalable app that could use a single code base along with plugins or a different UI.
  • Reduced development costs and time: Compared to the traditional approach of maintaining a dedicated codebase for different platforms, universal apps save developers time when it comes to rewriting code, and this alone reduces development cost and time drastically.

Why Crowdbotics Uses React Native

At Crowdbotics, we support universal app development with the Crowdbotics platform using React Native (or RAD stack) because of its non-mobile libraries, rapid development, and community support. In our opinion, it's the best universal app approach available today and the solution for the future of app development.

If you're interested in building a universal app entirely from scratch, Crowdbotics provides expert PMs and developers to manage your app build. Get in touch with us today for a detailed quote and development timeline!