The basics of mobile application testing – where to start?

The most important thing is that there are many differences between mobile application testing compared to web app ones. That’s why you need to familiarize yourself with their characteristics. Therefore, a mobile tester should know:

We already have an introduction and we know how to download / install mobile apps on a mobile device. Now, let’s focus on the types of applications we distinguish:

Native apps are created using platform-specific programming languages ​​(Android – Kotlin, Java, iOS – Objective-C, Cel C and Swift). They usually provide better performance compared to other solutions by taking full advantage of the sensors and functions of the platform. However, the cost of their development is usually higher due to the fact that new functions must be implemented separately in each code base, i.e. for each platform separately.

A mobile app is accessed via a browser. It looks like a responsive website (RWD), and the functionalities are usually very limited and dependent on the browser capabilities.

Ways to build browser-based applications:

They provide the possibility of using the device’s potential better than browser-based applications. They enable access to native phone functions, such as the camera, which are limited or impossible to access via the web app. However, hybrid mobile applications do not use the full potential of the device like native ones. One example is the offline mode, which is not 100% maintained in the case of hybrid mobile apps. On the other hand, the advantage of a hybrid mobile application is certainly the fact that it can work on many platforms from one source of code. It can be said that a hybrid mobile app is a compromise between the universality of the solution, the costs of production and maintenance, users’ habits to native solutions, use of resources and efficiency, combining native and web solutions.

As I mentioned at the beginning, testing mobile devices is different from testing web apps. Here’s a list of problematic issues that may occur during mobile application testing, affecting their scope:

We use programming platforms to create mobile applications. In the case of Android, we use Android Studio, while in iOS – Xcode. Programming platforms often contain tools that are helpful not only in typical developer tasks, but can also support application development and mobile testing. They have many useful built-in tools, such as taking screenshots, extracting device / application logs, sending random events and notifications to the device, monitoring various parameters such as: memory and CPU usage, http traffic tracking, viewing the layout implemented in the application and creating virtual devices. These tools include Android Virtual Device (AVD) Manager, Android Debug Bridge (ADB), Android Device Monitor, Instruments for iOS, Layout inspector and Logcat. 

Some interesting tools found outside of programming platforms that can facilitate mobile testing are also:

Is that all? Of course not. The spectrum of tools useful in mobile application testing is very large, and specific tools are selected based on the current needs and the characteristics of the project. It is also worth noting that the development tools – hidden by default on the Android platform, available for iOS from the xCode level – are very useful and it is worth taking a closer look at them. However, this is an extensive and broad issue which needs a separate article. Due to the fact that the current post is about the beginnings of mobile app testing, I also do not include tools useful in mobile test automation.

According to the ISTQB syllabus, there are a great number of types of mobile application testing. In my opinion, these are the most important ones:

There are many different screen sizes, diagonals, resolutions in pixels per inch and dots per inch on the market. Using the information about the most frequently used ones, and taking into account their diversity, it is worth checking:

Mobile devices are equipped with many sensors such as GPS, thermometer, light sensor, accelerometer, etc.

In this test category, it is worth checking if the application works correctly for the sensors used, e.g. movement in different planes, different light intensity, sound, response to changes in settings, displaying the exact location when using Wi-Fi, cellular data, after loss and restoration of network connections and cellular data, network changes, whether the application uses biometric recognition correctly, NFC payments.

Modern smartphones have many functions performed in real time when we use the application. It is worth checking how the application behaves in typical interrupts, such as:

Verification includes correct operation of notifications in various situations (application in the foreground, in the background, closed, in “Do not disturb” mode, running on low battery) and checking whether the notification relates to a specific place in the application to which it redirects a user after selecting it.

Testing whether applications adhere to the settings for sound level, brightness, dark mode, text size, power saving, languages, do not disturb mode, etc. on the smartphone.

Installations from stores, by copying the file to a mobile device and installing from it. In addition to the regular installation / uninstallation / update, you can check e.g. canceling / interrupting / resuming, as well as verifying whether, e.g. after updating, the application data remains and it is possible to continue using it.

Application speed tests should be performed in case of: high CPU load, little phone disk space, high memory usage, battery load, and many interactions with the application.

With particular emphasis on verifying that the application:

Verification of the correctness of the release by downloading, installing and – if possible – verifying the application in the production environment.

The terms simulator and emulator are often misused interchangeably. Simulators mimic the system in which they run the application. Mobile apps tested on simulators run in the simulator, they do not run on the real device, so you cannot check functions such as battery usage, interrupts, etc.

Mobile apps compiled for deployment and testing on the emulator are compiled into real bytecode which can also be used by the actual device. So the emulator will run an exact copy of the operating system. The emulator models the hardware, it uses the same environment as the physical hardware, so it takes into account RAM, CPU, battery performance, etc. For device emulation you can use, for example, Android Studio, and Xcode for simulation.

I hope that the knowledge I shared has helped you clarify and organize some of the issues related to the beginnings of working in the field of mobile application testing. It was mostly about industry or technical issues, but you’re probably asking yourself a question: ‘Is it really for me?’. Let’s try to answer it by reviewing the soft features / skills that are useful in the professional mobile app testing process.

Testers communicate with team members on a daily basis. They must do it clearly and precisely. Try to imagine a programmer’s face receiving a message like, “I go to the mobile application, select a tab and it doesn’t work.” Exactly … that’s why the clarity of asking questions, description, the ability to briefly but readily describe the error is very important.

A tester should promote the qualitative thinking model among the entire project team, suggest process and application improvements, make developers aware that they are responsible for their code and should also test it. Apart from that, he should be able to substantively and assertively conduct talks with other members of the project team or other stakeholders of the software being developed.

Mobile application testers need to be creative and curious about the behavior of the application in different situations. Possible functional use cases, the amount of equipment that can be used, or the way of using the device according to one’s own needs, create a great number of possible options. Creativity helps you find more defects that, when corrected, result in better software quality.

Testers need to understand and analyze the technical aspects of the solution and be able to apply them in mobile testing. They will help you understand the mobile app and know when something is not working as it should.

The remaining features, the influence of which does not need to be further described and explained, include: awareness of continuous learning, critical thinking, effective time management and the ability to prioritize tasks.

So, answering the question: ‘Is it really for me?’, remember that nobody is born with a ready-made package of skills, knowledge and predispositions, and acquiring competences requires time, willingness, commitment and hard work. Nobody is perfect and not everyone has all of the above-mentioned features, but that doesn’t mean they aren’t good testers. Some features can be overcompensated with others. It is also worth remembering that both technical and soft skills can be worked on and developed along with experience. Good luck! 😊