How to write an Android application yourself: from idea to publication on Google Play

Creating your own application for Android is a task that seems difficult only at first glance. In fact, even without programming experience, you can develop a functional mobile application if you follow a clear plan and use modern tools. In this article we will analyze the entire process: from the formation of an idea to placing the finished product in Google Playwith an emphasis on practical steps and typical mistakes of beginners.

It is important to understand that development under Android does not require expensive equipment or licensed software. An average computer power, a free development environment Android Studio and basic knowledge Java or Kotlinare enough. If you have never programmed, it doesn’t matter: today there are application designers (for example, App Inventor or Thunkable), which allow you to assemble simple apps without writing code. However, for full-fledged projects with unique functionality, you will have to master the basics of development.

This article will be useful:

• 📱 Beginnerswho want to create their first application;
• 💡 Entrepreneursplanning to launch a mobile service;
• 🎓 Studentslearning programming in practice;
• 🔧 Enthusiastswho want to automate routine tasks on a smartphone.

We We will not delve into the theory of algorithms or the architecture of operating systems - we will focus on practical steps that lead to a working APK file. Ready to get started? Then let's proceed to the first stage - preparation.

1. Formation of ideas and analysis of competitors

Before writing code, decide what your application will solve. A common mistake newbies make is trying to create a “universal product” with dozens of functions. In practice, such projects are rarely completed. Start with a minimalist idea that can be implemented in 1-2 weeks. For example: what is the problem your application will decide. A common mistake newbies make is trying to create a “universal product” with dozens of functions. In practice, such projects are rarely completed. Start with a minimalist idea that can be implemented in 1-2 weeks. For example:

• 📝 Notepad with synchronization via Google Drive;
• ⏰ Timer for the method Pomodoro;
• 📊 Expense tracker with export to Excel;
• 🎵 Player for local audio files with smooth playback.

Once the idea is formulated, check if there are similar applications in Google Play. If there are competitors, analyze their reviews: users often write what is missing in existing products. For example, reviews of expense trackers may complain about a lack of support RUB or a complex interface. This will tell you how to make your application better.

To analyze competitors, use:

• 🔍 Search by keywords in Google Play (for example, "water tracker");
• 📊 Analytics services like App Annie or Sensor Tower (free versions provide basic statistics);
• ⭐ Reviews with a rating of 1–3 stars —pain points are most often described there.

⚠️ Attention: If your idea requires working with payments, geolocation or personal data of users, study Google privacy policy. Since 2023, applications without Privacy Policy do not undergo moderation.

2. Selecting development tools

To create Android applications, there are several approaches that vary in complexity and required skills. Let's consider the main options:

Tool	Difficulty level	Language/technology	Suitable for
Android Studio + Native	⭐⭐⭐⭐	Kotlin/Java	Full-fledged applications with maximum performance
Flutter	⭐⭐⭐	Dart	Cross-platform applications (Android + iOS)
React Native	⭐⭐⭐	JavaScript	Applications with web technologies, rapid development
App Inventor	⭐	Flowcharts (visual programming)	Simple utilities without complex logic

Optimal for beginners choice - Android Studio with language Kotlin. Here's why:

• 📌 Official Google support — all documentation and updates are released primarily for native development;
• 🛠️ Flexibility —you can implement any functionality, from working with the camera to machine learning;
• 📈 Demand - knowledge Kotlin is useful for finding a job (according to Stack Overflow, this is one of the most popular languages).

If you have never programmed, start with App Inventor - this is a web service from MIT, where applications are assembled from blocks, like a constructor LEGO. The disadvantage of this approach is limited functionality and the impossibility of publishing without additional manipulations. However, this is an excellent option for teaching programming logic. Google Play without additional manipulations. However, this is a great option for teaching programming logic.

⚠️ Attention: If you choose Flutter or React Native, keep in mind that such applications may weigh more than native ones and sometimes slow down on weaker devices. For simple projects the difference is unnoticeable, but for games or graphics-intensive applications it is better to use Kotlin/Java.

3. Installation and configuration of Android Studio

Android Studio is the official development environment (IDE) from Google, which includes all the necessary tools: code editor, device emulator, debugger and SDK manager. Download it from official website (version for your OS: Windows, macOS or Linux).

After installation, follow these steps:

Pay special attention to the setup Android Virtual Device (AVD) —this is the smartphone emulator on which you will test the application. Recommendations for choosing:

• 📱 Device: select Pixel 5 or Pixel 6 —they are close to “pure” Android;
• 🖥️ Android version: Android 13 (API 33) or later (but check the version usage statistics in your target audience);
• 💾 System image: Google Play Intel Atom (if you need services Google).

If the emulator is slow, try:

1. Reduce the screen resolution of the virtual device;
2. Use x86_64 instead of ARM;
3. Enable hardware acceleration in the emulator settings;
4. Test on a real device via USB debugging.

To connect a physical smartphone:

1. Enable Developer mode: go to Settings → About phone → Build number and press 7 times;
2. Activate USB debugging in the developer menu;
3. Connect your phone to the computer and confirm trust in the device.

What to do if Android Studio does not start?

If Studio does not start or gives errors, try:

Delete 1. `.AndroidStudio` folder in your home directory (save the settings if necessary).

2. Run Studio as an administrator (Windows) or via a terminal with sudo rights (Linux/macOS).

3. Check if there is enough disk space (minimum 3 GB required for SDK). data-i="170">4. Update Java to the latest version (Android Studio requires JDK 11 or later).

4. Update Java to the latest version (Android Studio requires JDK 11 or later).

4. Creating the first project and analyzing the structure

After setup Android Studio create a new project:

1. Select New Project → Empty Activity;
2. Specify the application name (for example, MyFirstApp);
3. Select language: Kotlin (recommended) or Java;
4. Set the minimum SDK version (for example, API 24: Android 7.0 for broad compatibility).

The project structure in Android Studio includes key files:

• 📄 MainActivity.kt — the main application screen (logic on Kotlin);
• 📄 activity_main.xml — interface layout (what is displayed and where);
• 📄 AndroidManifest.xml — application configuration (permissions, version, etc.);
• 📁 res/ — folder with resources (pictures, lines, styles).

Open activity_main.xml and switch to mode Design (visual editor). Here you can drag interface elements (buttons, text fields) with the mouse. For example, add a button Button and a text field EditTextso that the user can enter text and see it after clicking.

Now go in MainActivity.kt and add a button click handler:

button.setOnClickListener {
val userInput = editText.text.toString()
Toast.makeText(this, "You entered: $userInput", Toast.LENGTH_SHORT).show()
}

This code:

1. Gets text from fields editText;
2. Shows a pop-up notification (Toast) with the entered text.

Launch the application on the emulator or device (green button RunIf everything is configured correctly, you will see an interface with an input field and a button that responds to). click.

5. Fundamentals of programming for Android: what you need to know

To create not only the simplest utilities, but also full-fledged applications, master the basic concepts:

Concept	Why you need it	Use example
Activity	Application screen with user interface	Home screen, settings screen, profile screen
Intent	Move between screens or call system functions	Opening the camera, going to a website, sending an email
RecyclerView	Displaying scrolling lists	News feed, chat list, image gallery
SharedPreferences	Saving simple data (settings)	Dark theme, interface language, last open tab
Retrofit	Working with network requests (API)	Downloading weather, exchange rates, news

For example, to open a web page by pressing a button, use Intent:

button.setOnClickListener {
val intent = Intent(Intent.ACTION_VIEW, Uri.parse("https://example.com"))
startActivity(intent)
}

To work with the network (for example, downloading data from a server), connect the library Retrofit. Add a dependency to build.gradle (Module: app):

implementation 'com.squareup.retrofit2:retrofit:2.9.0'

After synchronizing the project, you can create an interface for the API and make a request:

interface ApiService {
@GET("users/{id}")
suspend fun getUser(@Path("id") userId: Int): Response
}

⚠️ Attention: Since 2023 Google Play requires that all network requests be made through HTTPS. If your API uses HTTP, requests will be blocked. To bypass this limitation (for example, for testing), add to AndroidManifest.xml:

<application android:usesCleartextTraffic="true"..>

But in the final version of the application HTTP cannot be used!

6. Testing and debugging the application

Testing is a critical step that many beginners skip. Even a simple application can contain bugs that will only appear on certain devices or versions of Android. Use the following tools:

• 🐞 Logcat — error log in Android Studio (shows crashes and warnings);
• 🔍 Profiler — analysis of CPU, memory and energy usage;
• 📱 Firebase Test Lab — testing on real devices in the cloud (free for a limited number of tests).

Checklist for testing before release:

If the application crashes, study stack trace v Logcat. For example, the error:

java.lang.NullPointerException: Attempt to invoke virtual method on a null object reference

means that you are trying to use an object that is not initialized (equal null). A common reason is accessing a markup element that is not in XML or not linked in the code.

For testing on real devices:

1. Collect APKa file via Build → Build Bundle(s) / APK(s) → Build APK;
2. Transfer the file to your smartphone (for example, via Google Drive or ADB);
3. Install by allowing installation from unknown sources (Settings → Security).

If you are testing on devices from different manufacturers (Samsung, Xiaomi, Huawei), please note that they may have their own shells (for example, One UI, MIUI), which affect:

• 🔋 Working with the battery (background processes can be blocked);
• 📡 Permissions (some manufacturers request them separately);
• 🎨 Interface display (font size, icons).

How to test on iOS without a Mac?

If you are developing a cross-platform application (for example, in Flutter), you will need a Mac to test on iPhone with Xcode installed. Alternatives:

1. Use cloud services like BrowserStack (paid).

2. Ask friends with an iPhone to test the assembly.

3. Buy a used iPad mini (the most budget option for testing).

7. Preparing for publication on Google Play

Before uploading the application to Google Play It is necessary to prepare several required elements:

Element	Requirements	Tools for creation
Icon	Size 512×512 px, PNG format, no transparency	Figma, Adobe Illustrator, Canva
Screenshots	Minimum 2 screens for each type of device (phone, tablet, Android TV)	Emulator + Android Studio Screen Record
Description	Up to 4000 characters, with keywords for ASO	Google Docs + services like AppTweak
Video presentation	Duration up to 2 minutes, demonstration of key functions	OBS Studio (screen recording) + CapCut (installation)

For publication you will need:

1. Register a developer account in Google Play Console (one-time payment $25);
2. Create signed APK or App Bundle (Build → Generate Signed Bundle / APK);
3. Fill out a form with privacy information (mandatory from 2021).

When filling out the privacy form, please indicate:

• 🔐 What data the application collects (for example, email for registration);
• 📤 How data is used (for example, for authorization);
• 🗑️ Is data deleted upon uninstallation.

⚠️ Attention: If your application is intended for children (target audience under 13 years old), you will need to comply COPPA (US Children's Privacy Act B). In this case, you cannot collect personal data without parental consent. For details, see Google documentation.

After downloading, the application will undergo moderation (usually takes 1-3 days) If violations are found (for example, there is no privacy policy or the application crashes), they will send you a letter demanding correction. errors.

8. Promotion and monetization of the application

Publishing in Google Play is only half the success. In order for your app to be found by users, you will need promotion. Main channels:

• 📢 ASO (App Store Optimization) — optimization of the page in the market (title, description, keywords);
• 📱 Social networks — publications in Instagram, TikTok, Telegram-channels;
• 💰 Advertising — targeted campaigns in Google Ads or Facebook Ads;
• 🤝 Affiliate apps - reviews on YouTube or blogs.

For monetization, use:

Model	Suitable for	Cons
Paid application	Niche utilities with unique functionality	Difficult to compete with free ones analogs
Advertising (AdMob)	Applications with a large audience	May annoy users
In-app purchases	Games, applications with premium functions	Complicated setup (a server is required to validate purchases)
Subscriptions	Services (fitness, education, news)	High competition, constant support needed

For example, to connect AdMob:

1. Register on admob.google.com;
2. Add a dependency to build.gradle:

   implementation 'com.google.android.gms:play-services-ads:22.6.0'

3. Place a banner in the markup:

   <com.google.android.gms.ads.AdView
   android:id="@+id/adView"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   ads:adSize="BANNER"
   ads:adUnitId="ca-app-pub-3940256099942544/6300978111"/>

⚠️ Attention: Since 2026 Google Play requires you to indicate which ad libraries your application uses, even if you connected them indirectly (for example, through another SDK). Check dependencies using the tool Play Console.

FAQ: Answers to frequently asked questions

🔹 Do you need to know Java to write in Kotlin?

No, Kotlin is an independent language, but it the syntax is partially compatible with Java. If you know Javait will be easier to switch to Kotlin , but it is not necessary. For beginners Kotlin it is even preferable due to its more concise syntax and modern capabilities (for example, coroutines for asynchronous tasks).

🔹 Is it possible to make money from applications without unnecessary water?

Yes, alternative monetization models:

• 💎 Paid application (one-time purchase);
• 📦 In-app purchases (for example, unlocking premium features);
• 📅 Subscriptions (monthly payment for access);
• 🤝 Affiliate apps (for example, cashback for purchases through your application).

You can also combine models: free version with limited functionality + paid extension.

🔹 How long does it take development of a simple application?

Time depends on complexity:

• ⏳ 1–3 days — an application with one screen (for example, a calculator);
• ⏳ 1–2 weeks — a utility with multiple screens and data saving (for example, a water tracker);
• ⏳ 1 month+ —an application with network requests, authorization and complex logic (for example, a client for Trello).

Please note that testing and fixing bugs can take as much time as writing code.

🔹 Do I need to register an individual entrepreneur to publish on Google Play?

No, individuals can publish applications without registering as an individual entrepreneur or company. However:

• 💳 Payments will be sent to your personal account (you will need to provide passport data for verification);
• 📝 Taxes: if income exceeds 600 thousand rubles. per year (for the Russian Federation), you will need to register as a self-employed person or individual entrepreneur;
• 🌍 For some countries (for example, the USA) you may need ITIN (tax number for foreigners).

If you are planning a serious project with high income, consult with a consultant