How I Built 28 Apps and Make $10K/Month: A Developer's Portfolio Approach

Introduction

Meet Max, a full-time iOS developer who revolutionized his approach to app development. For years, he poured his energy into a single pet project, trying different growth techniques with little success. Then everything changed when he discovered a radically different strategy: instead of perfecting one app, he would ship dozens of simple apps as fast as possible.

In just eight months, Max built and launched 28 mobile apps while working his full-time job. This portfolio approach took him from making $200 a month to consistently earning $10,000 monthly. His fastest build? A complete app shipped to the App Store in just two hours. With over 1,000 subscribers across all apps and 4,000-5,000 daily active users, Max proves that success doesn't require one perfect app—it requires a portfolio of tiny bets.

Summary: Key Takeaways

The Portfolio Approach Works: Max's 28 apps generate $10,000/month, with just four apps contributing the majority of revenue (about $1,500 each). This demonstrates the 80/20 rule in action—you don't need every app to succeed.

Speed Over Perfection: Max can ship apps in hours, not months. His fastest build took just two hours from idea to App Store submission. He achieves this by reusing code, leveraging AI tools, and focusing on single core features.

Data-Driven Idea Selection: Using ASO tools like Astro, Max targets keywords with at least 20% popularity and 60-70% difficulty. He validates ideas by checking competitor revenue using Sensor Tower, only building when top apps make at least €100-200 monthly.

Lean Tech Stack: Despite earning $10,000/month, Max's total operating costs are remarkably low—around $300/month for all 28 apps. He leverages Flutter, Firebase free tier, and AI coding assistants to keep expenses minimal.

Ship and Move On: Max's philosophy is simple: build one core feature, ship it bug-free, and immediately move to the next project. Let data decide which apps float and which sink, then double down only on the winners.

From Failure to Portfolio Success

Max's journey began like many developers—with a single passion project that consumed endless hours but generated no results. As an iOS engineer with eight years of experience, he knew how to build apps technically, but the traditional approach of pouring everything into one project wasn't working.

The turning point came in February when Max discovered a YouTube video by Adam that completely changed his perspective. Instead of the conventional wisdom of focusing all effort on growing one app, he learned about a different strategy: building simple apps with single features, shipping them quickly, and moving on to the next project.

This paradigm shift was revolutionary for Max. He realized he could leverage his development skills not to build the perfect app, but to create a portfolio of small bets. It removed the emotional attachment to any single project and transformed failure from devastating to merely informative.

The Systematic Approach to Finding Profitable Ideas

Max's success starts with his rigorous process for identifying app opportunities. He doesn't build based on passion or intuition alone—he follows a data-driven methodology that maximizes his chances of finding profitable niches.

The ASO Tool Strategy

Max's primary tool for idea generation is Astro, a well-known App Store Optimization (ASO) platform. His process begins with keyword research:

Pick a category he's interested in or wants to explore
Search for relevant keywords and related terms
Identify closely related keywords that target the same user group but solve slightly different problems

For example, in the education category, he might target "physics AI," "chemistry AI," and "math AI"—different keywords but the same student demographic. This clustering strategy allows him to quickly jump between related niches after building one app, reusing much of the code and knowledge.

The Numbers That Matter

Max has specific metrics he looks for when evaluating keywords:

Minimum 20% popularity score in the ASO tool
60-70% difficulty score (low enough to rank but popular enough to matter)
Competitor revenue validation using tools like Sensor Tower

His benchmark is clear: top competitors must be making at least €100-200 per month. If apps in that space are making less, the market isn't worth his time. This prevents him from wasting weeks building apps in dead-end niches.

Live Example: Tree Identifier

Max demonstrates his process using a "tree identifier" keyword example:

Create a temporary app in Astro
Add the target keyword
Review related apps and keywords
Filter by popularity (20%+) and difficulty (70% or less)
Identify promising variations like "wood identification"
Check App Store revenue for top competitors
If revenue looks good, proceed to build

This systematic approach takes the guesswork out of idea validation and ensures Max only invests time in markets with proven demand.

The Lightning-Fast Build Process

Max's ability to ship apps in hours rather than weeks is what makes his portfolio approach viable. His process is highly optimized through code reuse, AI assistance, and ruthless focus on core features.

Step 1: Study the Competition

Max starts by analyzing two to three top competitors in his target keyword. But he doesn't get lost in their features—he focuses exclusively on the main feature that relates to his target keyword. Everything else is noise.

Step 2: AI-Powered Planning

Max uses ChatGPT or Gemini to generate detailed implementation plans. He provides:

The app concept and target keyword
Specific UI/UX constraints
Request for complete development roadmap

The AI generates screen layouts, feature breakdowns, and user flow structures, removing the guesswork and giving Max a clear blueprint to follow.

Step 3: Build with Reusable Components

This is where Max's portfolio approach truly shines. Instead of building from scratch:

Drag and drop UI elements from previous projects
Reuse settings screens, onboarding flows, and paywalls
Copy up to 90% of code from similar apps in his portfolio

For some apps, the majority of the work is simply adapting existing components to a new use case. This modular approach transforms a week-long project into a few hours of work.

Step 4: Design and Metadata

Once the app functions properly:

Open Figma and create a new project
Copy screenshot and app icon templates from previous apps
Use ChatGPT to generate app descriptions
Fill in all metadata, ensuring keyword optimization
Submit to App Store review

Max's entire workflow—from idea to submission—can take as little as two hours for simple apps, though most take about a week given his full-time job commitments.

The 6-Step Playbook for Shipping Apps

Max breaks down his complete process into six actionable steps that anyone can follow:

Step 1: Find Strong Keywords

Begin with keyword research using ASO tools. Ensure the popularity-to-difficulty ratio is favorable and verify that top apps are generating real revenue. Don't waste time in markets that don't pay.

Step 2: Study Competitors and Define Core Feature

Review the top apps in your target category. Analyze what they do well and identify the single core feature that solves the main user problem. Choose to solve that problem better or more efficiently—but keep it focused on one feature.

Step 3: Plan Fast with AI

Use AI tools like Cursor or Claude to generate a clear development roadmap. Request detailed breakdowns of:

All required screens
Feature specifications
User flows and navigation

This clarity helps you understand what to build fresh versus what you can copy from previous projects.

Step 4: Build Lean and Ship Quickly

Focus exclusively on shipping a clean MVP with only the features necessary to deliver value. Resist the temptation to add "one more feature" that will make it perfect. Perfect is the enemy of shipped.

Step 5: Release and Move to the Next Build

Once the app is functional, polished enough, and bug-free, release it and immediately move on to your next project. Let the data decide which apps sink and which float.

When you launch an app, you get an initial App Store boost. Over time, this fades. Monitor whether your app:

Keeps declining (it's sinking)
Stabilizes or grows (it has potential)

Don't try to force growth on sinking apps. The data will tell you which apps deserve more attention.

Step 6: Return to Winners and Scale with Ads

After some time passes, revisit apps that show organic traction or strong retention metrics. For the ones that float:

Polish and refine features
Fix bugs and improve UX
Add advertisements to monetize traffic
Consider paid user acquisition

This is when you double down—but only after the market has validated your app organically.

Tech Stack and Costs: Lean and Profitable

One of the most impressive aspects of Max's operation is how lean he runs it. Despite generating $10,000 monthly from 28 apps, his total operating costs are minimal.

Development Stack

Flutter: Max's primary framework for app development. Its cross-platform capabilities allow him to potentially target both iOS and Android, though he currently focuses on iOS.

Fastlane: A free automation tool that speeds up the deployment process, handling tedious tasks like screenshots, metadata management, and App Store submissions.

Cursor: An AI-powered coding assistant that helps Max write code faster and solve problems more efficiently.

Firebase: Max's all-in-one backend solution, providing:

User authentication
Database storage
Analytics
Website hosting

Most importantly, Firebase's generous free tier means Max rarely exceeds the included limits.

OpenAI and Gemini: Used for image recognition features and AI-powered functionality within apps.

Mixpanel: Analytics platform for tracking user behavior and app performance.

Astro: ASO tool for keyword research and competitor analysis.

AppFigures: App analytics and sales tracking for iOS.

Monthly Cost Breakdown

Max's transparency about costs reveals the profitability of his approach:

Cursor: $20/month
Fastlane: $0 (free)
OpenAI: $200/month (his highest cost)
Gemini: $50/month
Firebase: $5-10/month (mostly free tier)
Mixpanel: $0 (free plan)
Astro: $10/month
AppFigures: $0 (free plan)

Total monthly costs: Approximately $285-290

This means Max keeps roughly $9,700+ of his $10,000 monthly revenue—an exceptional profit margin for a software business.

The Most Important Advice: Don't Fear Shipping

When asked for his single most important piece of advice, Max's answer was unequivocal: don't be afraid of shipping.

Too many developers fall into the trap of endless polishing, thinking that one more killer feature will guarantee success. Max's experience proves otherwise. His advice:

Get your app bug-free with one single core feature, ship it, and let users tell you what they think while you're already building your next app.

This philosophy embodies several key principles:

Speed Creates Opportunity: The faster you ship, the more opportunities you create. Each app is a lottery ticket—you need many tickets to win.

User Feedback Over Your Assumptions: Your users will tell you what matters through their behavior. Don't assume you know what they want.

Emotional Detachment: By immediately moving to the next project, you avoid the emotional attachment that makes it hard to accept when an app doesn't work.

Data-Driven Decisions: Let metrics, not feelings, guide where you invest more time. The apps that float deserve more attention; the ones that sink don't.

Building the Shipping Muscle: Each launch makes the next one easier. You build a muscle for execution that compounds over time.

The Future of App Development

Max's success story represents a broader shift in how software gets built. With AI coding assistants, no-code tools, and cloud platforms offering generous free tiers, the barriers to building and launching apps have never been lower.

What matters now isn't just the ability to write code—it's the ability to:

Identify opportunities quickly
Ship products fast
Learn from data
Iterate without ego
Build systems that scale

Max's portfolio approach is particularly powerful because it embraces uncertainty. Instead of betting everything on one idea, he makes many small bets and lets the market decide winners. It's venture capital thinking applied to solo development.

The 80/20 rule in Max's results is revealing: four apps generate 80% of his revenue, but he needed to build 28 apps to find those four winners. You can't predict which apps will succeed, but you can control how many attempts you make.

Conclusion

Max's journey from struggling with one pet project to generating $10,000 monthly from 28 apps demonstrates the power of systematic execution over perfect planning. His success comes not from building the best apps, but from building the most apps with the best process.

The key lessons from his approach:

Validate ideas with data before building
Ship fast by reusing components and leveraging AI
Focus on one core feature that solves the main problem
Release and move on—let data guide future investment
Keep costs low with smart tool selection
Build a portfolio, not a single product

Perhaps most importantly, Max proved that you don't need to quit your job or go all-in on one idea to build a successful app business. You can do it in your off-hours by building a system that values speed, learning, and calculated risk-taking.

For developers looking to generate meaningful income from apps, Max's playbook offers a roadmap: build fast, ship faster, and let the market tell you what works. The courage isn't in perfecting one idea—it's in putting many imperfect ideas out into the world and learning from what happens next.