When organisations plan an app, they usually focus on features, timelines and design. But one of the biggest determinants of success happens long before a user ever sees a screen: whether the app performs consistently across the variety of devices people use every day.
Different screen sizes, hardware capabilities, operating system versions and network environments all influence how your app behaves. An app that runs perfectly on a single test device can feel slow or unreliable on the phones your customers actually carry.
This is why performance across devices needs deliberate planning. It doesn’t happen by accident, it comes from early decisions, careful testing and deep understanding of the mobile landscape. A senior, native mobile team brings the clarity and structure required to achieve this.
In this article, we’ll be exploring the key challenges and how to ensure your app performs reliably for everyone.
Challenge 1: Device fragmentation is greater than teams expect
Supporting multiple devices sounds simple at first, but anyone who has built mobile software knows it’s one of the most complex aspects. Android represents many active devices with different screen sizes and hardware capabilities. iOS is more controlled, but still varies across multiple models. Today, in Ireland, the market share between Android and iOS is fairly close at roughly 53.3% Android vs 46.5% iOS.
Internal teams used to desktop environments often underestimate this. They test on two or three devices and assume coverage is complete. But users don’t operate in that controlled environment.
How to overcome it: The solution is prioritisation. Experienced mobile teams analyse market data and customer analytics to define a device matrix - the essential list of devices to test thoroughly, the secondary list to validate, and the ones to monitor. This prevents spiralling QA time while still delivering robust coverage.
Challenge 2: Hardware and OS differences affect performance
Even a well-designed app can feel sluggish on older devices. Processor speed, memory availability and platform updates all influence performance. Many organisations need to support a mix of modern and older devices, particularly in regulated or enterprise settings.
Without optimisation, these users experience slower load times, stuttering animations or unexpected crashes. These may be small issues, but they can significantly damage trust.
How to overcome it: Optimisation needs to start early.
Senior developers must profile performance throughout the build, not just at the end. They need to measure memory usage, rendering speed and responsiveness under real conditions. Native development is key here, as it aligns with platform expectations and allows fine-grained control when optimising for performance.
Challenge 3: Real-world network conditions are unpredictable
An app may run perfectly on a stable office Wi-Fi network but behave very differently in rural areas where signal varies.
If an app isn’t built for fluctuating connectivity, users see frozen screens, lost progress or unexplained failures.
How to overcome it: Build for the real world by designing predictable offline behaviour, giving clear user feedback during interruptions and simulating poor network conditions during QA. These steps create an experience that feels resilient, not fragile.
Challenge 4: UI layouts don’t always adapt well across screens
Layouts that appear polished on a flagship phone can break on smaller or larger devices. Text may wrap awkwardly, buttons may fall below the fold or spacing may look inconsistent.
These issues are often caught late simply because the early design and development process focused on a single reference device.
How to overcome it: A flexible design system prevents these problems from emerging. Components are built with scalable constraints, adaptive typography and spacing rules that respond to different screen sizes. Early prototyping across device types allows teams to catch layout issues before development begins.
Challenge 5: Testing across devices is often underestimated
Testing isn’t just checking that screens load. It’s validating behaviour across screen sizes, OS versions, orientations, network conditions and real-world usage patterns. Small issues that slip through here quickly become large frustrations for end users.
How to overcome it: A structured QA plan is essential. This includes regression testing, usability testing, physical device testing and performance validation on both new and older hardware. Native development supports this by providing stable tooling aligned with each platform’s behaviour, making issues easier to diagnose and fix.
Challenge 6: Performance monitoring after launch is an afterthought
Many organisations see launch day as the finish line, but real performance insights emerge only once the app is in users’ hands. Crash patterns, slow screens and layout problems often correlate with specific devices or OS versions.
If no monitoring is in place, these issues go unnoticed until users complain.
How to overcome it: Implement analytics, crash reporting and performance monitoring from day one. A mobile partner who remains involved post-launch can interpret this data, diagnose causes and prioritise improvements. This ensures performance remains strong as devices evolve.
Why organisations work with Tapadoo
We’re brought in when teams want confidence that their app will perform consistently across the full device landscape. We see ourselves as an extension of your team. Our goal is to bring clarity, structure and reliability to your mobile strategy so your app feels fast, trustworthy and polished for every user.
If you want support ensuring your app performs across devices, we’d be happy to chat. Tapadoo is built on strong relationships and long-term support - because successful apps come from genuine partnership.
Thanks for reading the Tapadoo blog. We've been building iOS and Android Apps since 2009. If your business needs an App, or you want advice on anything mobile, please get in touch