What you need to start programming Android apps

To program Android applications, you need three things: Android Studio (the official development environment from Google), the Java or Kotlin programming language, and a computer with enough power to run the software. Android Studio is free and includes everything — the code editor, the Android SDK (the toolkit that lets your code talk to Android phones), and a simulator so you can test your app without owning a physical device.

Your computer should have at least 8 GB of RAM and 4 GB of free disk space. Android Studio runs on Windows, Mac, and Linux. You do not need to own an Android phone to start — the built-in emulator creates a virtual phone on your screen that behaves like a real one.

The choice between Java and Kotlin matters less than you might think at the start. Kotlin is newer and what Google now recommends for new projects, but Java is still widely used and has more learning resources online. Both languages do the same job; Kotlin is slightly shorter to write. If you are completely new to programming, either one will teach you the same concepts.

Key Takeaways

  • read Android Studio for free from Google's website, then install the Android SDK and create a test project to make sure everything works.
  • Android apps are built from Activities (screens the user sees), Services (work that happens in the background), and Resources (images, text, and layouts).
  • Your code tells Android what to display, what happens when the user taps a button, and how to store data — the Android system handles everything else.
  • Testing happens in the emulator first, then on a real phone if you have one, because the emulator sometimes misses problems that show up on actual hardware.
  • Publishing to the Google Play Store requires a developer account ($25 one-time fee), a signed APK file, and screenshots and descriptions of what your app does.

Installing Android Studio and setting up your first project

Go to developer.android.com and read Android Studio. The installer is large — around 900 MB — and the full SDK adds another 5 to 10 GB once installed. Open the installer and follow the prompts. When it asks about the Android SDK, accept the default location unless you have a specific reason not to.

After installation, open Android Studio. It will ask you to create a new project. Choose "Empty Activity" as your template — this gives you the simplest starting point. Name your project something straightforward like "MyFirstApp". Android Studio will create a folder structure with all the files you need: Java or Kotlin code files, XML layout files (which describe what the screen looks like), and a manifest file (which tells Android what your app can do).

Before you write any code, test that everything is working. Click the green play button in the toolbar. Android Studio will build your app and launch it in the emulator. You should see a blank screen with "Hello World" text. If this works, your setup is complete.

Understanding the parts of an Android app

Every Android app is made of Activities, Services, Broadcast Receivers, and Content Providers. You do not need all of them for a straightforward app, but understanding what each does helps you know where to write your code.

An Activity is a single screen that the user sees. A calculator app might have one Activity (the calculator screen). A messaging app might have one Activity for the conversation list and another for reading a single conversation. When you tap the back button, you leave an Activity. Your code in an Activity says what buttons and text fields to show, and what happens when the user taps them.

A Service is work that happens without a screen. A music player uses a Service to keep playing music even when the user switches to a different app. A weather app might use a Service to read new weather data every hour in the background. Services run even when the user is not looking at your app.

Resources are the images, text strings, colors, and layouts that your app uses. Instead of writing the word "Login" directly into your code, you put it in a resource file. This makes it straightforward to change the text later or translate your app into another language without touching your code.

Writing code that responds to user actions

The most common thing you will write is code that runs when the user taps a button. In Android Studio, open the layout file (usually called activity_main.xml). This file describes what the screen looks like — it is written in XML, not Java or Kotlin. You can drag and drop buttons and text fields into the layout, or write the XML by hand.

Give your button an ID so your code can find it. Then in your Activity code (MainActivity.java or MainActivity.kt), write a method that runs when that button is tapped. For example, if you have a button with ID "submitButton", you would write code like: find the button, then tell it "when someone taps you, run this code". The code might update text on the screen, save data to the phone's storage, or send information to a server.

Android handles all the hard parts — detecting the tap, running your code on the right thread so the screen does not freeze, and updating the display. You just write what should happen, and Android makes it happen.

Storing data so it persists after the app closes

If your app needs to remember something — a user's name, a high score, settings they changed — you need to save it to the phone's storage. Android offers several ways to do this, and which one you use depends on how much data and what kind.

SharedPreferences is the simplest. It stores small pieces of data as key-value pairs — like a dictionary where you ask for "username" and get back "Sarah". Use this for settings, login tokens, or a single high score. The data stays on the phone even after the app closes.

SQLite databases are for larger amounts of structured data — like a list of 500 contacts, each with a name, phone number, and email. You write SQL queries to find, add, or delete contacts. Android includes SQLite built-in, so you do not need to install anything.

Files are for anything else — images, documents, or custom data formats. You write data to a file in the phone's storage and read it back later. This is more work than SharedPreferences but more flexible.

Testing your app in the emulator and on a real phone

The Android emulator is a virtual phone that runs on your computer. It is slow compared to a real phone, but it is free and you can test without owning a device. To launch the emulator, click the play button in Android Studio. The first time takes a minute or two; after that it starts faster.

Test everything: tap every button, type in every text field, rotate the phone (press Ctrl+F12 on Windows or Cmd+F12 on Mac to rotate the emulator), and check that your data saves and loads correctly. The emulator can miss problems that show up on real hardware — for example, performance issues or bugs that only happen on certain Android versions.

If you own an Android phone, connect it to your computer with a USB cable. Enable Developer Options (go to Settings, About Phone, and tap Build Number seven times), then turn on USB Debugging. Android Studio will detect your phone and let you run your app on it. Real phones are much faster than the emulator and will catch problems the emulator misses.

Preparing your app for the Google Play Store

Before you can publish, you need a Google Play Developer account. Go to play.google.com/console, sign in with a Google account, and pay the $25 one-time registration fee. This is a one-time cost, not a monthly subscription.

Next, you need to create a signed APK — a packaged version of your app that proves you are the one who made it. In Android Studio, go to Build > Generate Signed Bundle / APK. Choose APK, then create a keystore file (a file that holds your signing key). You only create this once; keep it safe because you need it to update your app later. Android Studio will generate an APK file that is ready to upload.

In the Play Console, create a new app and fill in the details: the app name, a short description, screenshots (at least two), a full description, and your contact information. Choose a category (Games, Productivity, Social, etc.) and a content rating. Upload your APK, review everything one more time, and click Publish. Your app will appear in the Play Store within a few hours.

Common problems and how to fix them

The emulator is slow or will not start. Make sure your computer has virtualization enabled in the BIOS (this is a setting in your computer's firmware). If you are on Windows, make sure Hyper-V is turned off in Windows Features. If you are on Mac with an M1 or M2 chip, use the ARM version of Android Studio, not the Intel version.

Your app crashes when you tap a button. Open the Logcat window in Android Studio (View > Tool Windows > Logcat) and look for a red error message. The error message usually tells you exactly what went wrong — a null pointer, a missing resource, or a permission you forgot to request. Fix the problem and run the app again.

The app works in the emulator but crashes on your real phone. This usually means a permission issue (your app tried to access the camera or contacts but did not ask permission first) or a difference in Android version. Check the AndroidManifest.xml file to make sure you have requested all the permissions your app needs. On Android 6 and later, you also need to ask for permissions while the app is running, not just in the manifest.

Frequently Asked Questions

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

No, but it helps. If you have never programmed before, spend a week learning the basics of Java or Kotlin first — variables, loops, if statements, and functions. Codecademy and freeCodeCamp both have free courses. Then come back to Android. You will understand what is happening instead of just copying code.

Can I program Android apps on a Mac?

Yes. Android Studio runs on Mac, and the process is the same. The emulator is slower on Mac than on Windows, especially on older machines, but it works. If you have an M1 or M2 Mac, read the ARM version of Android Studio, not the Intel version.

What is the difference between an APK and an AAB?

An APK is a single file that installs your app. An AAB (Android App Bundle) is a newer format that the Play Store uses to create smaller APKs for each phone — so a phone with a small screen gets a smaller read. For your first app, publish an APK. Once you are comfortable, switch to AAB.

How long does it take to learn Android programming?

You can build a straightforward app (a calculator, a to-do list, a weather display) in a few weeks if you already know how to program. If you are starting from zero, plan on two to three months of regular practice. Complex apps with databases, networking, and background services take longer.

Do I have to use Android Studio?

Android Studio is the official tool and what Google supports, so it is the best choice for learning. Other tools exist — Flutter, React Native, and Xamarin let you write once and run on both Android and iOS — but they have a steeper learning curve and less documentation for beginners.