7 Testing Gaps That Cause 95% Of Mobile App Crashes

There's nothing more frustrating than a mobile app that crashes right when you need it most. After all, we only use them for everything in our lives, from connecting with friends to managing businesses. So you can understand why users have zero tolerance for unstable apps.

In fact, a recent report on mobile app stability indicates that apps with crash-free rates below 99.7% consistently receive poor ratings, usually below three stars.

For a mid-sized app, that translates to thousands in lost revenue every month.

So is your reputation and revenue at the mercy of unforgiving users? As a tech lead for a mobile-first startup, I can tell you with a resounding NO! By addressing the seven gaps we’ll cover, you will have eliminated 95% of scenarios that could cause your app to crash.

Let’s consider the first.

1. Device Fragmentation 

The vast variety of devices today poses a significant challenge for building stable mobile applications. Different manufacturers, models and screen sizes, hardware capabilities, operating systems, and your app needs to work well across:

One bug might appear only on specific combinations of hardware and software, making it hard to catch during regular testing. This problem is particularly challenging for Android apps. Each manufacturer creates their own modified version of Android, which means an app that runs perfectly on a Samsung phone might crash on a Google Pixel. It is impossible to test your app on every device out there. So, how can you address this challenge?

Do this:

• Prioritise Key Devices and OS Versions: Focus your testing efforts on the most popular devices and operating systems among your target users. That way, you cover most of your audience without spreading yourself too thin. You can’t satisfy everybody.
• Use Cloud-Based Testing Platforms: Tools like MagicPod and BrowserStack let you test on thousands of real devices without owning them. This broadens your testing scope and is also more cost-effective.

Implementing these strategies helps you manage device fragmentation while keeping costs reasonable.

2. Unpredictable Network Conditions

Most mobile app tests are conducted under ideal conditions, with fast, stable internet connections in office buildings or homes. But your users face a different reality: Slow 3G connections, Unreliable public WiFi, Dead zones, switching between networks while moving.

This gap between testing and real-world conditions often leads to crashes when users try your app in less-than-perfect situations. How do you handle network challenges?

Do this:

• Test Network Changes and Implement Network-Friendly Features: Your app should work smoothly when users switch from WiFi to cellular data, signal strength varies, or even when the internet connection completely drops. Make your app network-friendly by showing clear messages when problems occur, saving important data locally, working offline when possible (like YouTube's offline video feature), and trying again automatically when connections improve.
• Simulate Various Network Scenarios: Tools like Charles Proxy and Network Link Conditioner let you test your app under different network speeds and conditions, even when you only have access to fast internet.

Now your app can gracefully handle poor network conditions, providing a smooth user experience even in challenging connectivity situations.

3. Memory Management Issues

Memory issues often start small but grow into major problems.

When your app keeps holding onto memory it doesn't need anymore, it takes up too much space, makes your app run slower, and eventually forces it to crash. This is especially problematic on devices with limited memory. So, how do you effectively manage memory?

Do this:

• Practice Good Memory Management: Good programming habits help prevent memory waste by freeing up memory as soon as you're done with it and not keeping references to things you no longer need. In React Native, for example, you can clean up listeners when a component unmounts.
• Track Memory Usage: Tools like Android Profiler or Xcode Instruments can help you monitor real-time memory usage and locate leaks.
• Check Often for Problems: Test for memory issues after adding new features, when updating existing code, and during regular testing sessions.

Catching leaks early in the development stage prevents bigger issues down the line.

4. Unhandled Exceptions

When code encounters problems it wasn't prepared for, like trying to use data that doesn't exist or accessing items beyond a list's end, your app can crash without warning.

To prevent exception-related crashes, do this:

• Add Safety Checks: Gracefully handle code that might throw errors. For instance, in JavaScript, you can do this by wrapping code that might throw exceptions in a try-catch statement to handle errors gracefully.

• Test with Bad Data: Try your app with unexpected inputs such as empty text fields, numbers where text should be, special characters, and very large or small values.
• Track Problems Automatically: Use error tracking tools like Crashlytics to record when and why crashes happen, show which users are affected, and help you find the source of problems quickly.

The goal is to catch problems before they become crashes and give users clear information when something goes wrong.

5. Managing Software Updates

Apps rely on many moving parts that change often, such as operating systems and external libraries. Crashes and bugs can appear when these components are updated, but your app doesn’t handle them.

For a stable mobile app, you need to take a proactive approach to software updates. So, how can you be proactive?

Do this:

• Staying Updated with OS Versions: Test your app against new iOS and Android versions, update your code to work with system changes, and check that old features still work on new systems.
• Monitoring External Libraries: Outdated libraries can introduce vulnerabilities or bugs. Replace outdated libraries with newer versions and pick libraries that get regular updates and have strong community support.

Following these practices helps maintain app stability across system updates and reduces the risk of compatibility-related crashes.

6. UI Problems

What seems like minor display issues can quickly become app-breaking problems. Issues like screen freezes during heavy tasks, broken layouts on different devices, and memory-intensive animations can seriously impact user experience.

To improve UI stability, do this:

• Follow Standard Design Rules: Each platform has its own best practices, such as Android Material Design guidelines and Apple's Human Interface guidelines. These standards exist to prevent common problems.
• Make Your App Run Faster: Build simple screen layouts, make images smaller, and cut down on fancy animations.
• Run Intensive Tasks in the Background: Don't let data loading block the screen, run calculations separately from display updates, and keep the main screen responsive while processing.

Finally, test across multiple devices and screen sizes to ensure your app functions well with different resolutions and orientations. Altogether, implementing these strategies will result in a responsive and stable interface that works well across all devices

7. Insufficient Testing on Real Devices

While simulators and emulators can mimic real devices to a great degree, they can't match all the quirks of actual devices. Real phones have unique characteristics that virtual testing misses, such as different ways of handling app permissions, varied processing speeds, real-world memory constraints, and actual touchscreen responses.

To implement better testing methods, do this:

• Test on Physical Devices: Prioritise testing on actual devices, especially those popular with your target audience.
• Gather User Feedback with Beta Testing: Release pre-launch versions to a select group to identify real-world issues before a full release.

Through comprehensive real-device testing, you can identify and fix issues that might be missed in simulated environments.

Stable Apps Gain User Trust

Each of these challenges requires specific attention and solutions to prevent app crashes effectively. By addressing these issues during development and testing, you can create more stable apps that users trust and are willing to pay for.

That is the end goal after all.

References

• Challenges in Mobile App Testing
• 25 Common Reasons for Mobile App Crashing
• Mobile App Stability Outlook 2024