Answer.

Manual testing of mobile applications is the process of verifying the operation of a mobile program through user actions on a device (or in an emulator) to ensure compliance with development requirements.

Background:

With the advent of smartphones, the focus of development and testing has shifted from desktop and web products to mobile. Mobile devices have a unique architecture, limited resources, variable networks, and distinct interface behavior, which has intensified the need for testing specifically on real devices, rather than just in emulators.

Problem:

Mobile applications operate on different OS versions, device models, with varying screen resolutions and internet speeds. Bugs often manifest on one platform and are absent on another. Some issues are related to multi-touch, sensors, restarts, or transitions between applications.

Solution:

Testing includes sequential stages:

Preparing devices, configuring emulators/real devices.
Checking the business logic of the interface and network functionality.
Testing behavior when Wi-Fi is turned off, incoming calls, or device locks.
Verifying interface adaptability and responsiveness.
Validating installation, uninstallation, and updates of the application.

Key Features:

Requires testing on real devices with different OS and resolutions.
It is important to consider behavior under changing connection states, calls, and notifications.
Scenarios with resource-dependent cases (GPS, camera, memory, battery) are necessary.

Trick Questions.

What types of bugs are most often overlooked when testing only on emulators?

Battery issues, performance speed, problems with sensors, push notifications, and hardware interactions only appear on real devices.

Why is it important to test applications on older versions of OS?

Because API support and the behavior of system functions (permissions, notifications) vary; often bugs manifest only on older versions of Android or iOS.

How does validation in mobile testing differ from desktop?

In mobile testing, it is mandatory to check reactions to non-standard scenarios (calls, SMS, loss of network), which is not relevant for desktop.

Typical Mistakes and Anti-Patterns

Testing only in emulators.
Ignoring unstable scenarios (battery drain, network loss).
Insufficient coverage of devices and OS.

Example from Life

Negative Case

Tested only on iPhone 14 and the latest Android through an emulator. After release, users with Android 7 and Xiaomi complained about the lack of push notifications and freezing when returning from a call.

Pros:

Fast testing, short beta period.

Cons:

Many critical bugs in production, loss of customers, negative reviews.

Positive Case

Tested on a pool of 10 devices (different brands, OS versions), tried scenarios with incoming calls, loss of internet, switching cameras. The result — bugs were found before release, requirements were met.