Step-by-Step Mobile App Testing Guide for Beginners
Everything you need to know to start testing mobile apps properly. What testing actually is, the types of testing that matter, how to write a basic test plan, and how to run your first real test.
What is mobile app testing?
Mobile app testing is the process of verifying that an app works correctly, performs well, and provides a good experience for users — before it reaches them. It covers everything from checking that the login button works to verifying that the app does not crash on a five-year-old device running a two-year-old Android version.
Testing is not optional. Apple and Google both test your app before allowing it into their stores. Users test your app every time they open it. The question is whether you find the problems first.
Types of mobile app testing
Functional testing
Verifying that every feature works as described. Does the login button log you in? Does the upload button upload the file? This is the foundation of all app testing.
Common tools: Manual testing, Espresso (Android), XCTest (iOS)
Usability testing
Verifying that real people can use the app without confusion. Does the onboarding flow make sense to someone who has never seen it? Can users find the settings menu?
Common tools: Human testing, observation sessions, user interviews
Performance testing
Checking that the app is fast, does not crash under load, and does not drain battery excessively. A 4-star app and a 3-star app often differ only in performance.
Common tools: Xcode Instruments, Android Profiler, Firebase Performance Monitoring
Compatibility testing
Verifying that the app works correctly across different device models, screen sizes, and OS versions. Device-specific crashes are extremely common.
Common tools: Real devices, Firebase Test Lab, AWS Device Farm, BrowserStack
Security testing
Checking that user data is protected, permissions are appropriate, and authentication is implemented correctly.
Common tools: Manual review, permission audits, OWASP Mobile Security Testing Guide
Regression testing
Re-testing all existing features after a code change to confirm nothing broke. Essential for every release.
Common tools: Automated test suites: Espresso, XCTest, Appium
How to test your first app: step by step
Understand what the app is supposed to do
Before you test anything, read the requirements or product brief. What are the core flows? What does success look like for a user? Write this down. Testing without requirements is guessing.
Write a test plan
A test plan is a list of what you will test, in what order, on which devices. It does not need to be formal — a numbered list in a notes app is sufficient. Without a plan, you will miss things every time.
Set up your test environment
Install the app on a real device, not only a simulator. Create a fresh test account with no prior data. Close background apps and start from a clean state. This is how a reviewer tests your app.
Run through core flows first
Start with the most critical path: typically registration, onboarding, and the primary feature. If this breaks, nothing else matters. Complete it before testing edge cases.
Test edge cases and error states
What happens if the user types nothing in a required field? What if they enter an extremely long string? What if they deny a permission? What if the network drops mid-upload? These are the states that reveal hidden bugs.
Test on a second device
Pick a device different from your first — older model, different OS version. Run the core flows again. Device-specific crashes are extremely common and only visible on that device.
Document everything you find
Write down every issue with: what you were doing, what you expected, what happened instead, and the device and OS version. A bug report without reproduction steps is difficult to fix.
Run a health check on the binary
Before any submission, upload your APK, AAB, or IPA to the AppTester Health Check. It will catch binary-level issues that reject apps instantly: debug builds, signing problems, missing manifests.
Writing a simple test plan
A test plan does not need to be a formal document. For a first-time tester, a simple numbered list of test scenarios is enough. Here is a minimal template:
Minimal test plan template
App name and version being tested
Device(s) and OS version(s)
Core flows to test (e.g. registration, login, main feature, settings, logout)
Edge cases to test (empty fields, long inputs, permission denial, offline mode)
Expected result for each test
Pass / Fail result and notes for each test
The most important beginner mistakes to avoid
Mistake: Testing only on a simulator
Fix: Real devices have hardware constraints, different memory management, and actual network conditions. Always test on at least one real device before submission.
Mistake: Testing as a logged-in power user
Fix: Create a fresh account and test from the very beginning. Store reviewers test your app as a first-time user.
Mistake: Testing only the happy path
Fix: Test what happens when things go wrong: wrong password, denied permission, network failure. These states reveal most of the real bugs.
Mistake: Not writing down what you find
Fix: Memory is unreliable. Write down every issue as you find it, including the exact steps to reproduce it.
Start with a free Health Check
Before you submit to any store: upload your APK, AAB, or IPA. The Health Check catches the most common binary rejection causes in 30 seconds.