Where Android applications are created: tools and development stages

In the world of the mobile ecosystem, the question of where applications are born physically and programmatically often causes confusion among newcomers. Many people think that development happens entirely on Google's servers or in the cloud, but in reality the code creation process begins directly on the developer's computer. It is here, in the local environment, that the logic, interface and functionality of the future product, which will subsequently end up on Google Play, are formed.

The main place where Android applications are created is a specialized integrated development environment (IDE). This is a set of software tools that combines a text code editor, a compiler, a debugger and a device emulator in a single space. Without such software, writing complex code would be almost impossible or would take an unreasonably long time.

Main development environment: Android Studio

The absolute industry standard today is Android Studio. This is the official IDE from Google, built on top of IntelliJ IDEA. It is in this app that 90% of all modern Android applications are written. It provides developers with a complete set of tools for working with the Kotlin and Java languages, which are core to the platform.

Inside Android Studio, a powerful visual layout editor has been created that allows you to design a user interface (UI) using drag-and-drop elements or through direct XML code. This significantly speeds up the screen layout process. In addition, the environment includes an advanced code analyzer that suggests errors before the app is launched, saving hours of debugging.

The key advantage of using this particular tool is its deep integration with Google services. The developer can test the application’s operation with maps, notifications and payment systems right while writing the code. For professional activities, installation and configuration Android Studio is a mandatory first step.

⚠️ Attention: Android Studio is a resource-intensive application. For comfortable operation, the system requires at least 8 GB of RAM (16 GB recommended) and an SSD drive. On older computers with HDD, compiling projects can take an unacceptably long time.

Alternative tools and cross-platform development

Although Android Studio dominates market, there are other places where Android applications are created, especially when it comes to cross-platform solutions. Developers who want to create an application for both iOS and Android often choose frameworks that work in other environments. For example, Flutter uses the Dart language and can be developed both in Android Studio and in Visual Studio Code.

Another popular direction is development in JavaScript using React Native. In this case, the code is written in lightweight code editors such as VS Code or WebStorm, and the build for Android occurs through the command line using Node.js tools. This allows web developers to quickly adapt to the mobile platform without a deep dive into the specifics of Java or Kotlin.

For simple tasks or prototyping, online compilers and application builders are also used. However, such solutions have serious limitations in terms of performance and access to system functions of the device. They are suitable for educational purposes, but are rarely used to create high-level commercial products.

• 🚀 Visual Studio Code - a lightweight editor for React Native and Flutter with a huge number of plugins.
• 🎨 Android Studio - a full-fledged environment for native development in Kotlin and Java.
• 🌐 Xamarin - a tool from Microsoft for development in C#, integrated into Visual Studio.
• 🧩 No-code platforms —online constructors for creating simple applications without writing code.

The process of compiling and assembling a project

The very moment when the written code turns into a finished application occurs during the build process. In a development environment, this process is controlled by the build system Gradle. It takes the source code, resources (pictures, icons, layouts) and libraries, and then compiles them into bytecode understandable by the Android virtual machine (ART).

The result of this work is a file with the extension .apk (Android Package) or .aab (Android App Bundle). An APK file is an installation package that can be directly transferred to a device for installation. The AAB format is more modern and is used for publishing on Google Play, as it allows the store to optimize the size of the application for a specific user device.

The compilation process includes several stages: resource processing, compilation of Java/Kotlin code into an intermediate format, bytecode optimization (R8/D8) and signing the application with a cryptographic key. Without a digital signature, no Android operating system will allow the installation of an application, as this violates security policy.

./gradlew assembleDebug

This command, executed in a terminal or build console, starts the process of creating a debug version of the application. In a real project, this process can take from several seconds to several minutes, depending on the power of the computer and the size of the code base.

What is the difference between Debug and Release builds?

The Debug version contains debugging information, is not optimized and is signed with a test key. It is intended for developer testing only. The release version is optimized, compressed and signed with the developer's personal key - it is the one that ends up in the application store.

Local testing and emulation

Before the application gets to real devices, it undergoes a thorough check in a virtual environment. Built into Android Studio Android Virtual Device (AVD) allows you to emulate the work of dozens of different models of smartphones and tablets. The developer can choose the Android version, screen size, resolution, and even the amount of RAM of the virtual device.

Emulators create a complete copy of the Android software environment on the computer. This allows you to test the application on different versions of the operating system, from old Android 8.0 to the latest Android 14 and above, without having physical devices. This is critical to ensure compatibility.

However, emulation cannot always replace real tests. Camera, GPS, Bluetooth, and motion sensors on the emulator are often inaccurate or limited. Therefore, final testing is always carried out on physical devices via USB debugging.

Test type	Tool	Advantage	Disadvantage
UI Testing	Layout Inspector	Visual analysis of elements	Statics only
Functional test	AVD emulator	Fast launch of different OS	High load on PC
Performance	Profiler	CPU and memory monitoring	Requires experience in reading graphs
Network traffic	Network Profiler	Analysis of HTTP requests	Does not show background OS processes

Code repositories and teamwork

In modern development, code is rarely stored on just one computer. Version control systems such as Gitare used for version control and collaboration. The application code is uploaded to remote repositories such as GitHub, GitLab, or Bitbucket. This allows the development team to work on different parts of the application at the same time, without conflicting with each other.

Here, in the cloud code storage, merging of changes (merge), code quality check (code review) and automatic assembly of projects (CI/CD) take place. Continuous integration servers take code from the repository, assemble the application, run autotests and generate a ready-made build for testers.

Using Git allows you to roll back to a previous version of the application if a new feature causes a critical error. This is a kind of “time machine” for the project, ensuring the safety of intellectual property and development history.

• 📂 Commit — saving changes in the local Git history.
• 🔄 Push/Pull — sending changes to the server and receiving updates from colleagues.
• 🌿 Branch — creating a separate development branch for a new feature without risking the main version.
• 🔀 Merge — merging code branches after completing work on a task.

⚠️ Attention: Never upload files with secret signing keys (keystore) or API tokens to public repositories. This can lead to compromise of the developer account and leakage of user data. Use environment variables or .gitignore files to protect sensitive data.

Publish: final point of creation

The final stage where the application comes to life for millions of users is the Google Play Developer Console. This is where the compiled file is loaded .aab, metadata is filled in, screenshots and descriptions are added. After passing moderation, the application becomes available for download.

The publication process requires strict adherence to the store rules. The application is checked for the presence of malicious code, compliance with the privacy policy, and performance on various devices. Mistakes at this stage can lead to the release being rejected and delaying the product's entry into the market.

The process does not end after publication. Developers continue to create updates, fix bugs and add new functionality. Each update goes through the same path: writing code in the IDE, testing, building and uploading to the developer console.

Frequently asked questions (FAQ)

Is it possible to create an Android application directly on your phone?

Technically, this is possible using special IDE applications such as AIDE or Sketchware, but the functionality of such tools is very limited. They are only suitable for learning or creating very simple scripts. For serious development, you need a computer.

Which programming language is best to choose to start?

Today, Google officially recommends the language Kotlin. It is more modern, concise and secure than Java. Most of the new tutorials and documentation are focused specifically on Kotlin, so beginners are better off starting with it.

How much does it cost to publish an application on Google Play?

To create a developer account, Google requires a one-time fee of $25. After payment, the account is valid indefinitely, and you can publish an unlimited number of applications without a monthly fee.

Do you need to know mathematics to create applications?

For most typical applications (news, social networks, stores), basic logic and the ability to work with data are sufficient. Deep knowledge of higher mathematics is required only when developing games, graphic editors or applications with complex algorithms.