Just like any other software, mobile apps must be thoroughly tested before their release to ensure everything is working the exact same way it was intended.

While mobile app testing is already a lengthy and cumbersome process, the everyday introduction of new handheld mobile devices, operating system versions, and app testing tools has made the job of mobile app testers more complex and challenging than ever.

If you’re a beginner who is planning to kick off his career in mobile app testing, this guide will help you learn everything about it. Let’s get started with understanding what Mobile App Testing actually is!

What is Mobile App Testing?

In today’s highly competitive global marketplace, where the success of a mobile app is determined by the total number of downloads it has gotten, the positive reviews it has earned and the ranking it holds in the app store, the mobile app you’ve just developed must be impeccable to attract, engage, and retain users, and this can only be achieved by rigorous mobile app testing.

Mobile app testing is essentially the process of finding and fixing bugs in a mobile app in order to improve its overall quality, functionality, usability, and consistency, and making it as flawless as possible for users. Performed either manually, or automatically by the use of mobile app testing tools, or via a combination of both, mobile app testing if done rightfully not only ensures an immaculate and satisfactory experience for users but also plays a vital role in making the app popular and successful in almost no time. In short, mobile app testing is what every app needs to be flawless, successful and of high-quality.

Key Challenges for Mobile App Testing

Mobile app testing is much more complex than the traditional desktop testing and therefore presents a whole new set of challenges for testers and developers alike. Listed below are the key challenges that testers face while improving the quality and performance of a mobile app:

Different Types of Mobile Apps:

A big challenge in itself since a mobile app can be Native, Web or Hybrid. As each app type is built differently and quite different from each other in terms of both installation process and functionality, it needs to be tested in a completely different manner. The basic difference between each app type brings a number of challenges to mobile app testing.

A Variety of Mobile Devices:

One of the biggest challenges mobile app testers face is the wide variety of mobile devices available in the market today. These include smart phones, tablets, e-readers, wearable devices, and any other mobile device coming in the near future. Having different screen sizes, resolutions, input methods, and hardware capabilities, these devices present a completely unique set of challenges for mobile app testers.

OS Diversity:

Different mobile devices use different operating systems and different versions of a particular operating system are used by different devices at any given point of time. For instance, Android still has 8 different OS versions in use; on the other hand, 65% of Apple devices use iOS 11 while iOS 10 is installed on 28% of Apple devices and 7% still use earlier versions of iOS. Testing a single app across multiple mobile devices running on different versions of the same OS poses a unique challenge for mobile app testers.

Innumerable Manufacturers:

Another big challenge testers need to deal with is the continuously growing number of mobile device manufacturers. In 2015, there were just about 1200 mobile device manufacturers and at the beginning of 2018 itself, the counting has reached to over 1600. Undoubtedly, these numbers will only increase in the upcoming years. Different Hardware and software changes that manufacturers make to their mobile devices in order to distinguish themselves from each other have a direct impact on how an app works – making the testing process even more complex and challenging.

Connectivity Challenges:

Dealing effectively with a variety of connectivity options, such as different mobile networks (2G/3G/4G LTE/4G VoLTE and now 5G), Wi-Fi, Bluetooth, Infrared, etc, is no less than an acid-test. For all kinds of connectivity modes, the application must run smoothly under different network conditions like a change in the mobile network, roaming, weak network signals, no network coverage, slow connection speed, etc. However, this challenge is not counted as the big one for an offline app.

Continuous Testing:

In order to survive in today’s cutthroat competitive market, a mobile app needs to be updated frequently with new features and improvements. To meet this requirement, many developers prefer to use Agile Methodology over the traditional Waterfall approach, which leads to the continuous integration and deployment of the mobile app. Consequently, continuous testing of the app is required to ensure all the improvements are carried out correctly. This is also a very challenging practice for mobile app testers!

Choosing How to Test:

Another obstacle testers need to overcome is the selection of an appropriate mobile app testing approach with right mobile app testing tools. Where there are mainly two approaches (Manual and Automated) used for mobile app testing, on the other hand, the market is full of a variety of automated mobile app testing tools, making the selection of right testing tools a very confusing and tedious task unless one has a pre-planned testing strategy.

Different Types of Mobile App Testing

Like any other software, a mobile app also needs to be tested rigorously to ensure top-notch quality, usability and security. To achieve the same, several types of testing methodologies are used during mobile app development. Let’s take a look at what are they and how they differ from each other.

Functional UI Testing:

Being the most basic type of testing, Functional testing ensures that the app is functioning perfectly in accordance with the pre-defined user requirements. These tests are generally performed to check if the user interface and call flow of the application is working properly. However, if Functional testing is done manually, it often proves to be an extremely intensive, complex and time-consuming task due to several mobile-specific challenges.

Usability Testing:

Since the usability plays a vital role in determining the commercial success of any mobile application, Usability testing focuses mainly on three key areas of user experience: Efficiency, Effectiveness and User Satisfaction. These tests are conducted to ensure the consistency of user experience across all devices and check whether or not the mobile app is easy to use for end-users.

Compatibility Testing:

Compatibility testing is performed to check if the app is rendering well on different mobiles devices, screen sizes, browsers, resolutions, and OS platforms and versions. For example, a mobile app that is functioning properly on a smart phone may behave in a completely different manner on a tablet. Thus, compatibility testing evaluates the functionality of an application on different mobile devices and platforms.

Memory Leakage Testing:

Also known as Low-level Resource Testing, Memory Leakage Testing refers to checking how efficiently the app is utilizing the inbuilt memory of the mobile device it is being used on. It primarily includes the testing of overall memory usage, auto-deletion of temporary files after a certain period, and growing issues of the local database. As mobile devices are very limited in terms of memory as compared to desktop devices, memory leakage testing is exceptionally crucial to ensure the proper functioning of a mobile application.

Performance Testing:

The fundamental objective of Performance Testing is to ensure the application is able to deal with various mobile device challenges such as bad network coverage, switching the connection from mobile network to Wi-Fi, sharing something outside the app, low available battery or memory, application speed, simultaneous use of the app by many users, and other similar conditions. In other words, Performance testing is carried out to check the mobile app, network and server performance.

Interruption/Operational Testing:

An app while functioning may be interrupted by several events occurring on the mobile device, such as calls or SMS, pop-up notifications, insertion or removal of power cable, battery removal, network outage and recovery, low battery warning, etc. Interruption Testing is performed to check if the mobile app is able to withstand all these interruptions by closing itself every time an event takes place and restarting automatically afterward.

Installation Testing:

Installation testing verifies that the application can be installed, uninstalled or updated in a reasonable amount of time without the user having to face any difficulty. During this testing phase, mobile app testers not only take care for crashes that may occur during these three processes, but also they ensure all the app data will be removed completely from the device storage once the uninstallation process is completed.

Security Testing:

This involves verifying that the security and data privacy of users is not at stake within the app with the help of various techniques such as vulnerability scanning, log views, penetration testing, war dialing, virus detection, password cracking, etc. The main purpose of Security Testing is to improve the confidentiality, authenticity, and integrity of the mobile app.

Localization Testing:

Localization Testing ensures the usability, functionality, and accessibility of the mobile app in a wide variety of geographical regions and time zones. This type of testing is performed particularly when you’re planning to translate your app into several languages or roll out it to different countries. Localization Testing is considered the last stage of app QA testing.

Regression Testing:

This type of testing involves re-running previously performed, successful tests to ensure the changes which have been made to the app code hasn’t re-introduced any old or new bugs. As regression tests can be performed over and over again during any of the four levels of testing (unit, integration, system, and acceptance), they are an ideal candidate for automated testing.

Helpful Tips for a Winning Mobile App Testing Strategy

If you really want to win at mobile app testing, developing a clear and robust testing strategy is something you must not overlook. A proper mobile app testing strategic plan not only helps you easily overcome above-mentioned mobile app testing challenges but also saves you from the depressing scenarios of app rejection. Following are the best practices you must follow to test your mobile app in an efficient and effective manner.

Automated vs. Manual Testing:

Mobile app testing, as already mentioned above, can be performed either manually or with the help of automated mobile app testing tools like Appium, SeeTest, Selenium, and Ranorex. Since either one or both approaches are used during different lifecycle stages of a mobile app, you must be an expert at choosing between them according to the situation. As automated mobile app testing is the key to successful regression testing during different development phases, it should be performed only in scenarios where:

• You have the most frequent test-cases
• Test cases have predictable results
• Test cases are easy to automate
• Test cases are very time-consuming or impossible to perform manually
• The application is continuously growing
• Mobile app development lifecycle is very long

On the contrary, Manual App Testing approach is based on human input, analysis or evaluation and should be used if the app contains new features and functionalities or requires testing only once or twice.

Emulators vs. Physical Devices:

Just like two approaches, there are two main ways of testing a mobile app: either through virtual device emulators or real-life physical devices. While the use of device emulators proves extremely helpful in the initial stages of app development for testing basic functionalities, they don’t work as efficiently as physical mobile devices in the later stages of testing, like Beta testing. There are three types of mobile device emulators:

• Device Emulator: provided by device manufacturers.
• Browser Emulator: simulate rendering for mobile devices in browsers.
• Operating System Emulator: provided by the operating system itself.

For getting best testing results quickly and efficiently, test your mobile app first on emulators to detect and fix as many bugs as possible. Once a satisfactory level of testing is achieved, you could move to test your app on physical mobile devices for a more real-life scenario.

Selection of Right Mobile Device Models:

Deciding which device or device model should be used to test the mobile app is probably the first thing that comes to any tester’s mind when creating a real-world testing environment. This can sometimes be really a difficult decision because the devices you’re choosing determine how your app will function on billions of other similar devices. Hence, below three key factors should be taken into consideration during the target device selection:

• OS Version
• Screen Size and Resolution
• Form Factor

If necessary, don’t hesitate to take several other factors such as internal memory, connectivity options, etc, into account while selecting the device model.

Consider Cloud Testing:

To take your testing efforts to a whole new level, you can also try cloud computing based mobile app testing. Providing a web-based mobile app testing environment, cloud testing allows you to deploy, test, and manage your mobile apps quickly and efficiently. In addition to reducing the overall project cost and time, cloud-based application testing also offers you several other benefits, like:

• Highly scalable, fully synchronized and pre-configured testing environments
• No need to invest in any other advanced testing tools, resources or configurations
• Reduces the possibility of defects caused by a mistakenly created or unstable test environment
• Saves testers from setting up on-premise test environments which are very time-consuming and often lead to project delays
• Supports testing for complex, dynamic, and dissimilar applications, which is nearly impossible in an in-house environment.
• Real-time testing results
• Automatic backups and recovery

Organize Beta Testing:

Beta testing is a great and effective way to analyze the functionality, and usability of a mobile app with the help of real end-users who are using real-world devices. This phase is indeed conducted to check how well the app is performing on real devices and networks as well as to ensure all the bugs were fixed before launch. If you’re testing an app for iOS, you can leverage the power of the free TestFlight tool to manage your Beta testing.

Likewise, you can also use the Google Play Console to distribute your Android app to trusted users and testers for beta testing through various Google Groups or Google+ communities.