How to build Cross-Platform Mobile Apps

A cross-platform mobile app is an application that is developed to work on multiple mobile operating systems, such as Android and iOS, using a single codebase. Cross-platform mobile apps can be developed using different frameworks or technologies, such as React Native, Xamarin, Flutter, and others.

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Difference between Native and Cross Platform Mobile App Development

Native Mobile App Development targets either the Android or iOS platform. These apps are developed keeping in mind the specifics of the target OS. Cross Platform Mobile App development is meant to work on multiple Operating Systems using a single codebase. Here are the core differences between Native and Cross Platform Mobile App Development:

Criteria	Native App Development	Cross Platform App Development
Programming Language for Development	Native Android App Development uses Java or Kotlin. While iOS development uses Objective-C or Swift.	Cross Platform App Development uses platform agnostic languages such as Dart, C#, JavaScript
Frameworks for App Development	It requires native SDKs and IDEs such as Android Studio or IntelliJ IDEA for Android and XCode and AppCode for iOS	Popular frameworks used for Cross Platform App Development are Flutter, Xamarin, Cordova, React Native, etc.
Cost	Native App Development is costly.	It is cost-effective.
Code Reusability	Code cannot be reused	It supports code reusability. Same codebase is used across multiple platforms
Performance	Native apps are faster. Compiling happens using the platform’s core programming language and APIs which makes it more responsive and faster	Cross Platform apps have additional layer of computation, which makes them slightly slower than native apps
Access to new features	SDK offers early access to new features	While you have to wait for a separate update to access the new features

Benefits of Cross-Platform Mobile App Development

Mobile App for Multiple Platforms : The most significant benefit of building on a cross-platform framework is that the output of the development process can be used on multiple platforms. This approach is best suited where business functionality is straightforward and a short time to market is the goal.
Reduced Development Cost : In a typical scenario, a tech product will need three separate development workflows – web, Android, and iOS. A cross-platform framework can bring down the required effort to less than half.
Agile Development Process : Understandably, the development process will consume fewer human hours when a single code base is used. The flexibility of choosing between native, web, and hybrid allows for optimizing development loads across sub-teams. i.e . CPU-heavy or gaming applications will require more native development and optimization than an e-commerce app.
Simpler Code Maintenance & Usability : Having one code base for multiple platforms means that when it comes time to add or remove functionality from the application, only one set of updates is sufficient for updating the application across platforms. Also, having a single codebase to perform testing means you don’t have to worry about scaling your testing efforts too much horizontally. You can instead focus on test case prioritization.
Easy Cloud Integration : Since this is a relatively recent phenomenon, the tools and platforms for cross-platform development are built keeping in mind the tech trends of the day, which means most of these platforms support modern development methodologies like CI/CD, automation, cloud-based deployments, visualizations, etc. With cloud-based testing platforms like BrowserStack Automate and App Automate, you get a highly configurable and modernized workflow, weaving DevOps and QAOps into an integrated setup.
Faster Time-to-Market and Customize : Because these platforms are built with the whole pipeline of mobile application development in mind, they come with tools, features, and extensions that support responsiveness, performance, and security—making the process more streamlined and efficient—resulting in a further reduction in the time to market for the product.
Uniform Design : Although hard to achieve in some cases, the design output of cross-platform development can be consistent and effective. Responsive design principles are incorporated into the essence of the program, using the hierarchy of components and micro-services to break down functionality at the front and back end, respectively.

Various frameworks are available for cross-platform mobile app development, which we will discuss further in this article.

Popular Cross-Platform App Development Frameworks

Most popular cross-platform frameworks utilize a single code base to generate apps for different platforms. This means you must code on the programming framework supported by the platform of your choice. Since translating one code base into multiple applications is not a trivial task, many popular options have their advantages and disadvantages regarding comparison.

Xamarin
React Native
Flutter
Cordova

Mobile app development cross platform

Here are some cross-platform app development frameworks:

1. Xamarin

Xamarin is an open-source, cross-platform app development framework owned by Microsoft. It is used for creating native cross-platform apps for Android, iOS, and Windows using C# and . NET. Xamarin apps are built using native user interface controls and provide a high-performance user experience.

Famous examples include apps for Fox Sports, Alaska Airlines, HCL, American Cancer Society, and BBC Good Food.

Pros of Xamarin	Cons of Xamarin
Xamarin uses C# for coding , which works seamlessly for Android and iOS.	Xamarin is free for individuals and startups; however, enterprises must buy a license for Microsoft’s Visual Studio.
Has a strong community of over 60,000 contributors from more than 3,700 companies.	It is not recommended for apps that demand heavy graphics because each platform has a different method for visually laying out screens.
Allows for sharing more than 75% of code across platforms for “write once, run anywhere” ease.	Offers limited access to certain important libraries that the app developers need for mobile app development.
It consists of a single tech stack for faster development.	There is a decent overhead owing to the various layers and wrapping mechanisms used by the Xamarin engine.

2. React Native

React Native is an open-source, cross-platform app development framework owned by Meta (prev Facebook). It is used for creating native cross-platform apps for Android, iOS, and Windows using JavaScript and TypeScript (a strongly-typed version of JS).

React Native and Xamarin are at the top regarding user adoption and popularity.

Instagram, Bloomberg, Pinterest, Skype, and Tesla are popular apps built on React Native.

Pros of React Native	Cons of React Native
Up to 80% of a codebase can be shared across platforms, depending on the app’s complexity. Code reusability significantly speeds the development process.	React Native is not entirely a cross-platform app framework. To use some functions as a camera or accelerometer, there is still a need to use native components meaning there will be a separate code for Android and iOS.
Allows for previewing results right away and offers ready-to-apply elements, thus shortening the developing time considerably	Since the framework is not built in conjunction with iOS or Android, it sometimes lags behind the native platforms. This is one of the reasons that led Udacity to stop investing in React Native for new features.
The Hot Reloading feature enables developers to see changes made in code within seconds, not minutes, like when using native technologies.	React Native lacks consistency when it comes to releasing updates

3. Flutter

Flutter is an open-source cross-platform app development framework owned by Google. It is used for creating native cross-platform apps for Android, iOS , and Windows using Dart . Some examples are Alibaba, BMW, Google Ads, and Tencent.

Many ready-made solutions for native apps enable developers to work with Continuous Integration platforms like Travis and Jenkins .

Pros of Flutter	Cons of Flutter
Hot Reloading feature enables developers to see changes made in code within seconds instead of minutes.	There is limited support with apps built on the Flutter framework like smart TVs and some popular third-party plug-ins.
Flutter is based on Dart, an object-oriented programming language that developers have found rather easy to acquire the skill for and is almost twice as fast as JS .	There are several libraries with ready-to-implement functionalities; however, Flutter still lacks when compared to native development because most native APIs cannot be accessed.
Flutter has a full set of widgets in Google’s Material Design and in Apple’s style with the Cupertino pack to help with the UI design implementation.	Since Flutter-enabled apps use built-in widgets, not platform widgets, the app’s size is usually bigger.

4. Cordova

The Cordova platform by Apache is a tool that can be used to create mobile applications for s Android, iOS, Windows Phone, etc., using CSS3 and HTML5 for rendering and JavaScript for logic.

It provides access to device-specific functions through JavaScript APIs so that developers can build apps using web technology instead of the native programming languages of each operating system (Java or Objective C). Since it uses web technologies, debugging is relatively easier.

Pros of Cordova	Cons of Cordova
Cordova is an open-source platform that is free to use and distribute.	It is hard to avoid platform-specific quirks, which may or may not lead to bugs in the final application.
It can be used to build apps for all the major and some discontinued mobile platforms, including Android, iOS, Windows Phone, BlackBerry, Firefox OS, Bada, and Tizen.	There is some grey area around functions being invoked by remote HTML. This adds to the widespread concerns over security as JavaScript allows for the manipulation of functional code during sessions.
Supports the use of many libraries, including Single Page Application (SPA) development frameworks like React , Vue , Angular , etc.	Adobe earlier owned it under the title phone gap; later, it was acquired by Apache and renamed Cordova. The transition might not be smooth, and some plug-ins have gaps in documentation and support.

Tools and Frameworks to test Cross-Platform Apps

Testing is crucial to ensure a consistent and seamless user experience:

Appium
Appium allows you to test cross platform mobile apps as it supports both Android and iOS platforms. You can also run multiple tests in parallel using Appium Grid. It supports testing both Native and Hybrid apps.
Selenium
Selenium apart from testing web applications, also supports mobile automation testing. It supports different programming languages, such as Java, Python, C#, and JavaScript.
BrowserStack App Live
BrowserStack App Live helps you test your cross platform app manually on real Android and iOS devices of different OS versions. It allows you to test under real user conditions and use features like biometric authentication, IP geolocation testing, network simulation, etc.
BrowserStack App Automate
BrowserStack App Automate allows you to automate testing of your cross platform app on real Android and iOS devices. It allows you to test over different OS versions and device combinations, under real user conditions and on native features like Camera Injection, Network Simulation, etc.

Challenges in Cross-Platform Mobile App Development

Building cross-platform mobile apps requires consideration of the differences between platforms. Developers must ensure that the app functions consistently on all platforms, while also taking into account the differences in hardware, software, and user experience on each platform.

Here are some of the core challenges faced in cross-platform mobile app development:

Performance hiccups because of inconsistent communication between the native and non-native components of gadgets is one of the most commonly reported issues with cross-platform applications. This could be avoided with a better understanding and implementation of the syntax or configuration parameters set during the definition of functions on the platform.
Cross-platform app developers have difficulty maintaining cross-compliance of apps across devices and operating systems. A chance for the application to meet a new challenge arises whenever a new version is released. That’s why it’s a healthy habit to read up on new system-level changes and update the application to the best of its capability.
Testing cross-platform applications is an inherently difficult challenge that is solved with the help of modern cloud-based testing infrastructure like BrowserStack.
Application behavior must be tested and evaluated on real devices. Every time you build an application, you must find the latest versions of several physical devices and build testing infrastructure.

Closing Notes

With a streamlined application development process, it is natural to expect the testing infrastructure to have effective features and robust capabilities. Automation is among the top priorities for all QA teams.

With mobile app development cross platform and testing them on such a wide range of test environments, you can recreate real user scenarios and device experiences.

You can adjust real-world variables like network conditions and geo-location.
Test accessibility features like navigability and screen readers.
You can test notifications on devices.
Also, access the developer tools section of browsers on various operating systems.

Analysis and data visualization are the two post-testing activities that will help you understand, arrange, document, and visualize what happened during the test runs. Plus, it records the application behavior if captured efficiently in visual formats.

Once you have achieved a healthy level of collaboration with the business teams on analyzing the results of the various levels of testing, you can make the most sound decisions for the future of your cross-platform mobile apps.

Frequently Asked Questions

1. How do cross-platform mobile apps differ from native apps in terms of performance and user experience?
Cross-platform mobile apps may have slightly lower performance than native apps, as they rely on a single codebase that has to work on multiple platforms. However, advances in cross-platform development frameworks have made it possible to develop apps that can match the performance of native apps. User experience can also be slightly different, as the UI may need to be adapted to work well on different platforms.

2. What is a cross platform mobile framework?
A cross-platform mobile framework is a tool or set of tools that allows developers to create mobile applications that can run on multiple operating systems. These frameworks provide a common codebase that can be used to build applications for both iOS and Android, as well as other platforms like Windows and Linux. Examples of popular cross-platform mobile frameworks include React Native, Flutter, Xamarin, Ionic, and PhoneGap. These frameworks typically allow developers to write code in a single language, such as JavaScript or Dart, and then translate that code to native code for each platform, providing a consistent user experience across multiple devices and operating systems.

3.What is cross platform testing?
Cross platform testing is a type of software testing where the compatibility of an application is tested on different platforms, devices, and browsers. It is a testing process that ensures that an application functions as intended on various operating systems, hardware, and software configurations.

4. Why is cross platform testing important?
Cross-platform testing is important because it helps to ensure that an application is functional, reliable, and delivers a consistent user experience across multiple platforms. It also helps to identify any compatibility issues that may arise due to differences in hardware, software, or operating systems. This type of testing is crucial for mobile applications, which must work on various devices and operating systems to succeed.

5. What is cross-platform with example?
Cross-platform refers to software or applications that can run on multiple operating systems or platforms. For example, a cross-platform mobile app developed using React Native or Flutter can be used on both iOS and Android devices, while a cross-platform desktop application developed using Electron can be used on both Windows and macOS.