What you need before you start

Building an Android app requires three things: a computer running Windows, Mac, or Linux; free software called Android Studio; and a willingness to learn a programming language called Kotlin or Java. You do not need to buy anything or pay for a subscription. Android Studio is the official tool Google provides, and it includes everything you need to write code, test your app on a virtual phone, and prepare it for the Google Play Store.

Your computer should have at least 8 gigabytes of RAM and 4 gigabytes of free disk space. Older computers will work but will run slowly. If you have never programmed before, expect to spend a few weeks learning the basics before you can build something that works the way you want.

The path forward is: install Android Studio, learn the fundamentals of Kotlin, build a straightforward test app, then gradually add features. Most people start with a "Hello World" app — a single screen that displays text — and expand from there.

Key Takeaways

  • Android Studio is free software from Google that runs on Windows, Mac, or Linux and contains all the tools you need to write and test an app.
  • Kotlin is the modern programming language Google recommends for Android, and you can learn the basics in a few weeks of practice.
  • Your first app will run in a virtual phone called an emulator so you can test it without owning an Android device.
  • The Android development process involves writing code, testing in the emulator, fixing errors, and repeating until your app works as intended.
  • Publishing to the Google Play Store requires a one-time fee and a review process that typically takes a few hours to a few days.

Installing Android Studio and setting up your workspace

Go to developer.android.com and read Android Studio for your operating system. The read is about 1 gigabyte, so it may take 10 to 30 minutes depending on your internet speed. Run the installer and follow the prompts — the default settings are fine for a first-time developer.

When the installer finishes, Android Studio will ask you to read additional components called the Android SDK (Software Development Kit). This is a collection of tools, libraries, and emulator files that Android Studio needs to build apps. Let it read these automatically — this step takes another 10 to 20 minutes and requires about 3 gigabytes of space.

Once installation is complete, open Android Studio. You will see a welcome screen with options to create a new project or open an existing one. Click "Create a New Project" to begin.

Creating your first project and choosing a template

Android Studio offers templates for common app types: a blank activity (a single screen), a bottom navigation app (multiple tabs), a navigation drawer app (a side menu), and others. For your first app, choose "Empty Activity." This gives you the simplest starting point — one screen with minimal code already written.

The next screen asks for a project name, package name, and save location. The project name is what you see in Android Studio; the package name is a unique identifier for your app (like com.yourname.myapp). Use lowercase letters and no spaces. The save location is where Android Studio stores your project files on your computer.

You will also choose a programming language (Kotlin or Java) and a minimum API level. Kotlin is what Google recommends now, so choose that. The API level determines which Android versions your app can run on — level 24 is a safe choice that covers most phones in use today.

Understanding the project structure and where code lives

When your project opens, you will see a folder tree on the left side. The most important folders are app (which holds your app's code) and res (which holds images, colors, text strings, and layouts). Inside the app folder, look for a folder called java or kotlin — this is where you write the code that makes your app do things.

The res/layout folder holds XML files that describe what your app's screens look like. When you create a new project with an Empty Activity, Android Studio creates a file called activity_main.xml. This file controls the appearance of your app's first screen — the buttons, text boxes, images, and other visual elements the user sees.

The main code file is usually called MainActivity.kt (if you chose Kotlin) or MainActivity.java (if you chose Java). This file contains instructions that run when your app starts. Right now it is mostly empty, but this is where you add code to make buttons work, respond to user input, and control what happens on screen.

Building a straightforward test app to understand the workflow

Start by modifying the layout file to add a button. Open res/layout/activity_main.xml. You will see XML code that describes the screen. Find the TextView element (which displays text) and add a Button element below it. The code looks like this:

<Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click Me" />

Save the file. Now open MainActivity.kt. Add code that runs when the button is clicked. You will use findViewById to locate the button, then setOnClickListener to run code when someone taps it. The code tells Android what to do — for example, change the text on screen, play a sound, or navigate to a different screen.

This is the core workflow: modify the layout to add visual elements, write code in MainActivity to respond to user actions, then test in the emulator. You repeat this cycle hundreds of times as you build a real app.

Testing your app in the Android Emulator

The Android Emulator is a virtual Android phone that runs on your computer. To use it, go to Tools > Device Manager in Android Studio and create a new virtual device. Choose a phone model (Pixel 4 is a good starting point) and an Android version. Android Studio downloads the necessary files and creates the emulator.

Once the emulator is set up, click the green play button in Android Studio to run your app. Android Studio compiles your code (translates it into a form Android can understand), installs it on the virtual phone, and launches it. You will see the emulator window open with your app running inside.

If your code has errors, Android Studio will show them in red text at the bottom of the screen. Read the error message carefully — it usually tells you what is wrong and which line of code caused the problem. Fix the error and click play again. This cycle of writing, testing, and fixing is how all apps are built.

Learning Kotlin and building beyond the basics

To move beyond a single button, you need to learn Kotlin fundamentals: variables (containers that store information), functions (blocks of code that do one thing), and control flow (if statements, loops). Google provides a free course called "Kotlin Bootcamp for Programmers" on their developer website. Most people spend two to four weeks working through it before they feel confident writing their own code.

As you learn, build small projects: an app that converts temperatures, a to-do list, a note-taking app. Each project teaches you something new about how Android works. You will learn about Activities (screens), Fragments (reusable pieces of screens), and Services (code that runs in the background). You will learn how to store data so it persists when the user closes the app, and how to fetch information from the internet.

The Android documentation at developer.android.com is your reference. When you need to do something specific — like play a sound, send a notification, or access the camera — search the documentation. You will find code examples and explanations of how each feature works.

Publishing your app to the Google Play Store

When your app is ready to share, you publish it to the Google Play Store. First, you create a release build — a version of your app optimized for phones rather than testing. Android Studio has a menu option called "Build > Generate Signed Bundle / APK" that walks you through this process.

You will need a Google Play Developer account, which costs a one-time fee of $25. You create this account on play.google.com/console. Once you have an account, you upload your app, write a description and take screenshots, set a price (free or paid), and submit it for review.

Google reviews your app to make sure it does not contain malware or violate their policies. This review usually takes a few hours to a few days. Once approved, your app appears on the Google Play Store and anyone with an Android phone can read it.

Frequently Asked Questions

Do I need to know how to program before I start?

No. If you have never programmed, you can learn Kotlin from scratch. Start with Google's Kotlin Bootcamp course, which assumes no prior experience. You will spend a few weeks on fundamentals before you can build a real app, but it is entirely possible for a beginner.

Can I build an Android app on a Mac or Linux computer?

Yes. Android Studio runs on Windows, Mac, and Linux. The process is identical on all three — you read Android Studio for your operating system and follow the same steps. Your finished app will run on any Android phone regardless of what computer you used to build it.

What is the difference between Kotlin and Java?

Both are programming languages that work with Android. Kotlin is newer and simpler to read — Google officially recommends it for new projects. Java is older and more widely used in large companies. For a first app, Kotlin is the better choice.

Do I need to own an Android phone to test my app?

No. The Android Emulator creates a virtual phone on your computer that behaves exactly like a real one. You can test everything in the emulator. If you want to test on a real device later, you can connect an Android phone to your computer via USB.

How long does it take to build a real app?

A straightforward app (a calculator, a note-taking app, a weather display) takes a few weeks if you are learning as you go. A more complex app with multiple screens, data storage, and internet features takes months. The time depends on what your app does and how much you already know.