What you actually need to make an app

Making an app means writing code that runs on a phone, tablet, or computer. You do not need to be a programmer already — you can learn as you go — but you do need to pick a language to write in, a way to test what you build, and a place to publish it when it works. The easiest path depends on what kind of app you want: something straightforward for one phone type, or something that works everywhere.

Most people start by choosing between two routes. The first is learning a programming language like Swift (for iPhones) or Kotlin (for Android phones), which gives you full control but takes longer to learn. The second is using a no-code or low-code platform like Flutter, React Native, or even visual builders like MIT App Inventor, which let you build faster but with less flexibility. Neither is wrong — it depends on what you want to build and how much time you have.

Key Takeaways

  • You need a programming language (Swift for iPhone, Kotlin for Android, or a cross-platform tool like Flutter), a code editor or IDE to write in, and a way to test your work on a real device or simulator.
  • iPhone apps go through Apple's App Store review process, which takes a few days to a week and has strict rules about what your app can do; Android apps go to Google Play and have fewer restrictions.
  • Learning to code takes weeks or months depending on how complex your app is, and most beginners start with tutorials and sample projects rather than building from nothing.
  • You will need a developer account ($99 per year for Apple, free for Google) and a computer powerful enough to run the development tools, though you do not need an expensive one.
  • Testing on a real phone is important because simulators do not catch all bugs, and you should plan to spend as much time fixing problems as you do writing the original code.

Picking a language and development environment

If you want to build for iPhone, you write in Swift using a tool called Xcode, which Apple provides free. If you want Android, you use Kotlin (or Java, which is older) in Android Studio, also free. Both tools are large programs that run on Mac or Windows and include everything you need: a code editor, a simulator to test on, and instructions for sending your app to the store.

If you want your app to work on both iPhone and Android without writing the code twice, you have options. Flutter uses a language called Dart and produces apps that feel native on both platforms. React Native uses JavaScript and is backed by Meta (Facebook). Both are free and have large communities posting tutorials. The trade-off is that cross-platform tools sometimes cannot do everything a native app can, and debugging is harder when something goes wrong.

For absolute beginners, MIT App Inventor lets you build straightforward Android apps by dragging blocks together instead of typing code — no programming experience needed. It is free and runs in your web browser. The apps you make are limited to straightforward tasks like sending texts or reading data from the internet, but it is a real way to see how apps work without learning syntax first.

Setting up your computer and accounts

You need a computer with enough space and memory to run the development tools. Xcode is about 12 gigabytes and works on any recent Mac. Android Studio is about 8 gigabytes and runs on Mac, Windows, or Linux. If you have a laptop from the last five years with at least 8 gigabytes of RAM, you are fine. You do not need a gaming computer or anything expensive.

Before you can publish, you need a developer account. Apple charges $99 per year and requires a credit card and a valid Apple ID. Google charges $25 once and requires a Google account. Both accounts let you publish unlimited apps. You do not need to pay anything to learn and test — only when you are ready to put your app in a store.

You should also set up a version control system like Git and GitHub. This sounds technical but it is just a way to save your code online and keep track of changes. GitHub is free and most tutorials assume you are using it. Learning Git takes an afternoon and saves you from losing weeks of work if your computer breaks.

Learning the basics through tutorials and sample projects

Do not start by trying to build your own idea. Start with a tutorial that walks you through building something small — a calculator, a to-do list, a weather app that fetches data from the internet. Google, Apple, and Udemy all have free tutorials. YouTube channels like Traversy Media and The Net Ninja have step-by-step videos where you follow along and type the same code they type.

Work through at least two complete tutorials before you start your own project. The first teaches you the language. The second teaches you how to think about building apps — how to organize your code, how to handle data, how to make things respond when the user taps a button. After two tutorials, you will recognize patterns and know where to look when you get stuck.

When you start your own project, pick something small. A note-taking app, a habit tracker, a straightforward game. Something you can finish in a month. Scope creep — adding features as you go — is the main reason people abandon projects. A finished small app teaches you more than an abandoned big one.

Testing on simulators and real devices

Both Xcode and Android Studio include simulators — fake phones that run on your computer. They are fast and convenient for testing, but they do not catch everything. A simulator cannot test how your app behaves when the network is slow, when the battery is low, or when the user switches apps and comes back. It also cannot test how your app feels to actually use — the speed, the responsiveness, the way buttons feel under your finger.

You should test on a real device as soon as you have something that works. If you have an old iPhone or Android phone lying around, use that. You can connect it to your computer with a USB cable and run your app directly on it. Xcode and Android Studio both make this straightforward — there is a button that says "Run on Device" and it handles the rest.

Plan to spend as much time testing and fixing bugs as you spent writing the code. Most of your time will be in this phase: finding problems, understanding why they happen, and changing your code to fix them. This is normal and expected. Professional developers spend more time debugging than coding.

Submitting to the App Store or Google Play

When your app is ready, you package it and send it to Apple or Google. For iPhone, you use Xcode to create what is called a "build" and upload it through App Store Connect, Apple's submission website. Apple reviews your app — checking that it does not crash, that it follows their design rules, that it does not do anything deceptive. This takes three to seven days. If they reject it, they tell you why and you fix it and resubmit.

For Android, you upload to Google Play Console. Google's review is usually faster — sometimes a few hours — and their rules are less strict. You set a price (or free), write a description, upload screenshots, and hit publish. Your app goes live within hours.

Both stores require you to write a description, take screenshots, and pick a category. Spend time on this. A clear description and good screenshots are the difference between people finding your app and nobody knowing it exists. You are competing with millions of other apps, so make it obvious what yours does in the first two sentences.

Common problems and what to do about them

Your app will crash. This is not a sign you are doing it wrong — it is part of the process. When it crashes, the development tools show you an error message that tells you which line of code caused the problem. Read the error carefully. Search for the exact error message on Google or Stack Overflow (a website where programmers answer questions). Someone else has almost certainly hit the same problem and posted the answer.

Your app will be slow. This usually means you are doing too much work on the main thread — the part of your code that handles what the user sees. The fix is to move slow tasks (like downloading data from the internet) to a background thread. This is a common pattern and every tutorial covers it.

Your app will not work the way you expected. This is usually because you misunderstood how the language works, not because you are bad at programming. Read the documentation. Look at sample code. Try a simpler version of what you are trying to do. Build up from there.

Frequently Asked Questions

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

No. You can learn a programming language while building your first app. Start with a tutorial that teaches the language and a straightforward project at the same time. Most people learn faster by doing than by studying theory first.

How long does it take to build a straightforward app?

A basic app — something with a few screens and straightforward features — takes two to four months if you work on it a few hours a week. This includes learning time. If you already know the language, it takes two to four weeks. Complex apps with lots of features take much longer.

Can I build an app on Windows for iPhone?

No. Xcode only runs on Mac, so you need a Mac computer to build iPhone apps. You can build Android apps on Windows, Mac, or Linux. If you only have Windows, start with Android or use a cross-platform tool like Flutter.

What if my app gets rejected by the App Store?

Apple tells you why it was rejected. Common reasons are crashes, unclear descriptions, or features that violate their rules. You fix the problem, resubmit, and it usually gets approved the second time. Rejection is not permanent.

Do I need to pay to publish my app?

You need a developer account ($99 per year for Apple, $25 once for Google). You do not need to charge money for your app — you can make it free. Either way, you pay the account fee to publish.