What you actually need to do to build an app
Building an app means deciding what problem it solves, designing how it works, writing the code, testing it on real devices, and putting it in an app store or on the web. You do not need to know how to code before you start — you can learn as you go, hire someone to code for you, or use no-code tools that let you build without writing code at all. The path you choose depends on your budget, timeline, and how complex your app needs to be.
Most people underestimate how long this takes. A simple app — something with a few screens and basic features — typically takes three to six months if you are working alone and learning as you go. A more complex app with user accounts, payments, or real-time data can take a year or longer. The biggest mistake is starting to code before you have written down what the app actually does.
Key Takeaways
- Write down exactly what your app does, who uses it, and what problem it solves before you write any code or spend any money.
- You can build an app by learning to code yourself, hiring a developer, or using no-code platforms like Flutterflow or Bubble — each path has different costs and timelines.
- Testing on real phones and tablets is essential because apps behave differently on different devices, and you cannot catch all problems in a simulator.
- Launching means getting your app into the Apple App Store or Google Play Store, which requires accounts, fees, and approval processes that take one to two weeks.
- After launch, you will need to fix bugs, add features, and keep the app working as operating systems update — this is ongoing work, not a one-time project.
Define what your app does before you build it
Write a one-page description of your app that answers these questions: What does it do? Who uses it? What problem does it solve for them? What does the user see when they open it? What buttons or screens do they interact with? This document is called a specification or spec, and it saves you months of wasted work.
Sketch the screens on paper or in a tool like Figma (free tier available). You do not need beautiful designs — stick figures and boxes are fine. The goal is to see the flow: what happens when a user taps a button, where do they go next, what information do they enter. Tools like Miro or even Google Drawings work for this. Share your sketches with people who might use the app and ask them if it makes sense.
Decide which platform you are building for first. An app for iPhone only is simpler and faster than an app for both iPhone and Android. A web app (something you use in a browser) is often faster to build than a native app (something you download from an app store), but it cannot do everything a native app can. Write down your choice and why.
Choose how you will build it: code, hire, or no-code
If you want to learn to code yourself, start with the platform you chose. For iPhone apps, learn Swift using Apple's free tutorials and Xcode (Apple's free development tool). For Android, learn Kotlin using Google's free tutorials and Android Studio. For web apps, learn JavaScript, HTML, and CSS using free sites like freeCodeCamp or Codecademy. Expect to spend three to six months learning the basics before you can build something real. This path is free but slow.
If you want to hire a developer, you have three options: hire a freelancer on Upwork or Toptal (usually $50 to $150 per hour), hire a small agency (usually $5,000 to $50,000 for a simple app), or find a co-founder who codes. Get three quotes and ask each person to estimate the timeline based on your spec. Check their past work and talk to previous clients. This path costs money but is faster if you find someone good.
If you want to use a no-code platform, tools like Flutterflow, Bubble, or Adalo let you build an app by dragging and dropping components instead of writing code. You can build a simple app in weeks. These platforms charge monthly subscriptions (usually $20 to $200 per month) and limit what you can do — you cannot build something as complex as Instagram or Uber. This path is fast and cheap but limited.
Build the app in stages, not all at once
Do not try to build everything at once. Start with the minimum viable product or MVP — the smallest version that solves the core problem. If you are building a to-do list app, the MVP is: create a task, see your tasks, mark a task done, delete a task. That is it. No themes, no sharing, no notifications. Build that first.
Once your MVP works and you have shown it to real people, add the next layer of features. This approach means you launch faster, get feedback from real users sooner, and do not waste months building features nobody wants. It also means you can change direction if you learn that people do not actually want what you built.
As you build, write down every bug you find and every feature request you get. Use a simple spreadsheet or a tool like Trello. Prioritize: fix bugs that crash the app first, then bugs that break core features, then everything else. Add features that multiple people ask for before features only one person wants.
Test on real devices before you launch
Testing in a simulator on your computer is not enough. Simulators do not behave exactly like real phones. Download your app onto an iPhone and an Android phone (if you are building for both) and use it like a normal person would. Try it on different screen sizes — a small phone, a large phone, a tablet. Try it on slow internet and fast internet. Try it with the screen brightness low and high.
Ask five to ten people who are not you to use the app and watch them. Do not explain how it works — just hand it to them and watch what they do. You will see problems you never noticed because you know how it is supposed to work and they do not. Write down every place they get confused or tap the wrong button.
Test the things that break most often: logging in, making payments, uploading photos, and anything that requires internet. If your app stores data (like a to-do list), test what happens if the user closes the app in the middle of saving. Test what happens if they lose internet connection. These edge cases are where most bugs hide.
Get your app into the app store
For iPhone, you need an Apple Developer account ($99 per year) and Xcode. For Android, you need a Google Play Developer account ($25 one-time fee). For web apps, you just need a domain name and hosting (usually $5 to $20 per month).
Each store has rules about what apps it will accept. Read the guidelines before you submit. Common rejections: the app crashes on startup, it does not work as described, it has no privacy policy, or it uses features in ways Apple or Google does not allow. Write a clear description of what your app does, take good screenshots, and write a privacy policy explaining what data you collect and what you do with it.
Submission takes one to two weeks for Apple and usually faster for Google. Apple reviews apps by hand, so rejection reasons can be specific. Google is mostly automated. If your app is rejected, read the reason carefully, fix the problem, and resubmit. Most apps get rejected once or twice before they are approved.
Plan for work after launch
Launching is not the end. Operating systems update (iOS and Android release new versions every year), and your app has to keep working with them. Users will find bugs you missed. People will ask for features. You will need to fix crashes, update code libraries, and add security patches.
Budget time and money for this ongoing work. If you built the app yourself, plan to spend a few hours per month on maintenance. If you hired a developer, negotiate a support contract (usually $500 to $2,000 per month for a simple app). If you used a no-code platform, the platform handles some updates automatically, but you still need to monitor your app and fix problems.
Track how many people use your app, where they get stuck, and what they ask for. Most app stores show you crash reports automatically. Use this data to decide what to fix and what to build next.
Frequently Asked Questions
Do I need to know how to code to build an app?
No. You can hire a developer, use a no-code platform, or learn to code from scratch. Each path takes different amounts of time and money. Learning to code takes the longest but costs nothing. Hiring is fastest but costs the most. No-code is in the middle.
How much does it cost to build an app?
A simple app built with no-code tools costs $200 to $500 in platform fees. A simple app built by a freelancer costs $3,000 to $15,000. A more complex app costs $20,000 to $100,000 or more. Learning to code yourself costs nothing upfront but costs your time.
How long does it take to build an app?
A simple app takes three to six months if you are learning to code, two to four months if you hire a developer, and two to eight weeks if you use no-code tools. A complex app takes a year or longer. The timeline depends on how many features you want and how much testing you do.
What is the difference between iOS and Android?
iOS is Apple's operating system for iPhones and iPads. Android is Google's operating system for most other phones and tablets. Apps built for one do not work on the other — you have to build them separately or use a tool that builds for both. Building for both takes roughly twice as long as building for one.
What happens if my app crashes after I launch it?
The app store will show you crash reports. Fix the bug, test it on a real device, and submit an update. Updates usually go live within a few hours to a few days. Users get a notification that an update is available and can download it. This is why testing before launch is so important — crashes hurt your rating and make people uninstall.