How to build Cross-Platform Mobile Apps

Building cross-platform mobile apps allows developers to create apps that run seamlessly on both Android and iOS using a single codebase, saving time and costs. Frameworks like Selenium and Appium are popular choices for this approach.

Testing these apps across different devices can be challenging, but tools like BrowserStack help by offering cloud-based testing on real devices, ensuring compatibility and performance.

This guide covers the tools, challenges, and best practices for building and testing cross-platform mobile apps effectively.

What is a Cross Platform Mobile App?

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.

What is Cross Platform App Development?

Cross-platform app development is the process of building mobile applications that can run on multiple operating systems, such as Android and iOS, using a single codebase. This approach lets developers write the app once and deploy it across different platforms, significantly reducing development time and costs.

Cross-platform development allows developers to create apps that run on both Android and iOS using a single codebase, eliminating the need for separate platform-specific development. Frameworks like Flutter, React Native, and Xamarin streamline the process, making it faster and more cost-effective.

Key benefits of cross platform app development include:

• Faster Time-to-Market: A unified codebase speeds up development and releases across platforms.
• Cost Efficiency: Reduces the need for separate teams, cutting development costs.
• Consistency: Ensures consistent performance and appearance across devices.
• Easier Maintenance: Updates and fixes are applied to all platforms simultaneously.

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:

Benefits of Cross-Platform Mobile App Development

Here are the Top 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. 

1. Xamarin
2. React Native
3. Flutter
4. Cordova
5. Ionic Framework

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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.

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.

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. 

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.  

5. Ionic Framework

Ionic is an open-source, cross-platform app development framework that uses web technologies like HTML, CSS, and JavaScript to build mobile applications. It’s based on Angular and React, providing native-like user experiences with a single codebase for both Android and iOS.

Famous Examples: MarketWatch, Sworkit, JustWatch, Nationwide.

How to Choose the right cross-platform app development framework for your project?

Selecting the right cross-platform app development framework is a critical decision that requires careful consideration of various factors. Here are key tips to guide you in making the best choice for your project:

1. Clarify Project Requirements

Before diving into framework options, it’s important to have a clear vision of your app’s goals. Define the key features, functionalities, and platforms you want to support. Think about the user experience and design you envision for your app. Understanding these aspects will help you narrow down frameworks that best align with your project’s objectives.

2. Define Your Budget and Timeline

One of the key advantages of cross-platform development is cost and time efficiency. However, you must still set a realistic budget for development, testing, and maintenance, as well as a timeline for launching the app. Choosing a framework that fits within your budget and can meet your time constraints will ensure you avoid unexpected expenses or delays.

3. Understand Your Target Audience

Knowing your target audience is essential for creating an app that meets their needs and expectations. Research user behaviors, preferences, and pain points to ensure that the framework you choose supports features that enhance the user experience and engagement. This will help you select a framework that prioritizes your users’ needs.

4. Evaluate Platform Compatibility

Cross-platform development’s main advantage is the ability to reach users on multiple platforms using a single codebase. However, not all frameworks are equally capable of supporting all platforms (iOS, Android, etc.). Ensure that the framework you choose can deliver consistent performance and design across all targeted platforms and devices.

5. Assess App Complexity

The complexity of your app plays a key role in framework selection. Simple apps might work well with frameworks like Ionic or React Native, while more complex apps that require extensive logic or advanced features may benefit from more robust options like Xamarin or Flutter. Understand the scope of your app’s requirements to choose a framework that can handle its complexity effectively.

6. Consider Required Features and Functionality

Different frameworks offer varying levels of functionality. Consider the specific features you need for your app, such as hardware access, third-party integrations, or native capabilities. Frameworks like React Native and Xamarin provide strong support for native features, while Ionic is ideal for web-based functionalities. Choose a framework that aligns with the functionality your app demands.

7. Focus on App Design

Your app’s design—whether it’s native, hybrid, or web-based—can impact the framework you choose. Some frameworks, such as Flutter and React Native, offer more flexibility in creating customized, high-performance UIs. If design is a priority for your app, choose a framework that supports the level of design freedom and consistency you require.

8. Plan for Maintenance

App maintenance is an ongoing process that involves updates, bug fixes, and ensuring the app remains secure. Consider the long-term maintenance efforts and resources needed for your app. Choose a framework that simplifies maintenance tasks, such as updates and debugging, to ensure your app stays functional and up-to-date.

Tools and Frameworks to test Cross-Platform Apps

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

• 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 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 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 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.

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Challenges in Cross-Platform Mobile App Development

Building cross-platform mobile apps presents several challenges due to the inherent differences between platforms, hardware, software, and user experiences. Developers must ensure consistent functionality across multiple platforms, all while considering these variations.

Here are some of the core challenges faced in cross-platform mobile app development, along with their solutions:

1. Performance Issues Due to Inconsistent Communication Between Native and Non-Native Components

Cross-platform apps often face performance hiccups because of inconsistent communication between native and non-native components of the device, which can affect speed and responsiveness.

Solution: To mitigate this, developers should have a deep understanding of the platform’s syntax and configuration parameters. Proper optimization of code for platform-specific requirements and efficient handling of native and non-native interactions can reduce performance bottlenecks. Additionally, using frameworks like Flutter and React Native that provide close-to-native performance can help.

2. Maintaining Cross-Compliance Across Devices and Operating Systems

As new device versions and operating system updates are released, maintaining cross-compliance and ensuring the app functions properly across all supported platforms becomes a complex task.

Solution: Developers must regularly monitor updates for iOS, Android, and other platforms to ensure compatibility. Building a testing process that includes regular checks for system-level changes and performing updates when necessary can help maintain app functionality. Leveraging frameworks with strong community support and frequent updates, such as React Native and Xamarin, can also assist in managing platform changes.

3. Complexity of Testing Cross-Platform Apps

Testing cross-platform applications can be difficult due to the need to ensure that the app performs consistently across different devices and platforms. This can be time-consuming and resource-intensive.

Solution: Using modern cloud-based testing infrastructure like BrowserStack can significantly streamline the testing process. These platforms provide access to a wide range of real devices, allowing developers to test their apps across various configurations without needing a large physical device inventory. Automated testing tools like Appium and Cypress can also improve testing efficiency by enabling tests to be run in parallel across multiple devices and platforms.

4. Device and OS-Specific Behavior and Compatibility

Challenge: Each device and OS version may exhibit slightly different behavior, requiring developers to test and optimize the app for various real-world scenarios.

Solution: Continuous testing on real devices is critical. Platforms like BrowserStack allow developers to test their app on multiple real devices and OS versions, ensuring it behaves as expected across all platforms. Additionally, developers should leverage responsive design techniques to ensure their app adapts seamlessly to various screen sizes and resolutions.

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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.

Conclusion

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. 

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