How to Build a Mobile App as a Solo Developer

What You're Building

A mobile app that runs natively on iOS and Android. This is one of the hardest things a solo developer can take on, but also one of the most rewarding. Mobile apps have built-in distribution through app stores, push notifications to re-engage users, and people are willing to pay for apps in ways they're not willing to pay for websites.

I shipped my first mobile app after about four months of evening and weekend work. It was a simple utility app, nothing fancy. But seeing it in the App Store with real reviews from strangers was genuinely one of the best moments of my developer career. Fair warning though, it was also one of the most frustrating projects I've ever worked on.

Difficulty & Timeline

Recommended Tech Stack

Here's my strong opinion on this. Unless you have a very specific reason to go native (like AR, heavy animations, or hardware integrations), use React Native with Expo. It's the best solo developer experience available for cross-platform mobile development in 2026.

Flutter is the other serious option, but Dart is a language you'll only use for Flutter. React Native lets you leverage your existing JavaScript/TypeScript knowledge and share logic with a web app if you ever build one.

For the backend, use Supabase. It gives you a database, authentication, storage, and real-time subscriptions out of the box. Pair it with Expo's EAS Build service for compiling and submitting to app stores without needing a Mac (well, you still need one for testing, but not for building).

Step-by-Step Plan

Phase 1: Foundation (Month 1)

Install Expo, create your project, and get it running on your physical phone immediately. Not the simulator. Your actual phone. This matters because the simulator lies to you about performance, touch interactions, and screen sizes.

Build your navigation structure first using Expo Router. This is the skeleton of your app. Define all your screens, set up tab navigation or stack navigation, and get the basic flow working. Every screen can just be a text component that says "TODO" at this point.

Set up Supabase, create your database schema, and implement authentication. Email/password plus Google and Apple sign-in. Apple requires Apple Sign-In if you offer any other social login, so don't skip it.

I made the mistake of leaving auth until month three on my first app. Retrofitting authentication into an existing app is painful. Do it first.

Phase 2: Core Features (Month 2-3)

Build the one thing that makes your app worth downloading. Not the settings screen, not the profile page, not the onboarding flow. The core feature. If your app is a habit tracker, build the habit tracking. If it's a photo editor, build the editing tools.

Use React Native's built-in components where possible, and reach for a UI library like Tamagui or NativeWind (Tailwind for React Native) for styling. Avoid heavy animation libraries until you actually need them.

Test on both iOS and Android throughout this phase. I cannot emphasize this enough. Fixing platform-specific bugs at the end is ten times harder than catching them as you go. The most common issues are keyboard handling, safe area insets, and permission dialogs behaving differently between platforms.

Phase 3: Polish & Launch (Month 4-5)

This phase takes longer than you think. App Store review can reject your app for surprisingly minor things. I got rejected once because my screenshot showed a status bar that didn't match the device frame. Another time because my privacy policy link was broken.

Create an App Store listing with good screenshots (use a tool like Screenshots.pro or Fastlane's snapshot), a clear description, and proper keywords. Apple's keyword field is 100 characters, and every character matters for ASO (App Store Optimization).

Set up push notifications with Expo Notifications. This is your biggest retention tool. A well-timed push notification can bring users back better than any email campaign.

Submit to both stores. Apple review takes 1-3 days. Google Play review takes a few hours to a couple of days. Have patience and be ready to fix review feedback quickly.

Monetization Strategy

The App Store and Google Play both take 30% of in-app purchases (15% for the first $1M/year on Apple). Factor this into your pricing.

Subscriptions work best for apps that provide ongoing value. A $4.99/month subscription converts better than a $49.99/year one, even though the annual is cheaper. People are weird about money. Offer both, but default to showing monthly.

For utility apps, a one-time purchase with a premium unlock works great. Charge $4.99-9.99 and give away a useful free tier. Ads are a last resort and honestly aren't worth it until you have at least 50k monthly active users.

One thing that works surprisingly well is offering a free trial of premium features. Seven days is the sweet spot. Apple even lets you offer introductory pricing, and apps that use it convert significantly better than those that don't.

Common Mistakes to Avoid

Going native for both platforms. You're one person. Building and maintaining two completely separate codebases in Swift and Kotlin is a full-time job times two. Use cross-platform tooling unless you have an extremely good reason not to.

Ignoring app size. A 200MB app is a hard sell for casual users. Keep your bundle lean. Lazy-load assets, compress images, and remove unused dependencies.

Skipping the onboarding flow. Users who don't understand your app in the first 30 seconds uninstall it. A three-screen onboarding that shows the core value is not optional. It's essential.

Not planning for offline. Mobile apps should work without internet, or at least degrade gracefully. Use local storage for critical data and sync when the connection comes back. I've seen apps crash on airplane mode because they didn't handle fetch errors. Don't be that developer.

Is This Worth Building?

It depends on your idea. Mobile apps are high-effort but also high-reward when they work. The distribution advantage of app stores is real. People discover apps differently than they discover websites, and the willingness to pay is higher.

But here's the honest truth. Most solo developer mobile apps fail not because the code is bad but because marketing a mobile app is brutally hard. App Store SEO matters, reviews matter, and getting those first hundred downloads is a grind. If you're building a mobile app, make sure you have a plan for how people are going to find it. "Build it and they will come" does not apply to the App Store. There are millions of apps there. You need a distribution strategy from day one.

If your app solves a real problem that people already search for, go for it. If it's a "nice to have" that you think would be cool, maybe validate the idea with a landing page and waitlist first. The four months you'd spend building could be saved by a two-week validation experiment.