I sold Newsletterytics
This was the first app that made me money on the internet. Five dollars. Two years later I sold it.
Read article →Writing by Paweł Karniej
Practical guides and case studies from building React Native apps, AI products, subscription systems, and App Store releases.

This was the first app that made me money on the internet. Five dollars. Two years later I sold it.
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App Store organic traffic still exists, but it can no longer carry an app business by itself. Distribution, software as content, and two B2B models I am watching.
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I ship quite a lot of apps. That doesn’t mean I should keep all of them alive.
Read article →Fix an AI-built app before launch by triaging auth, payments, analytics, device builds, and App Store blockers in the right order.
Read article →Apple rejected your AI-generated app? Classify the review issue, repair the right layer, and decide whether to fix or rebuild.
Read article →A release-focused triage plan for React Native bugs blocking TestFlight, App Review, payments, auth, or production launch.
Read article →Before submitting a Rork app, check the native build, auth, payments, privacy, analytics, and App Store assets that preview cannot prove.
Read article →Built a mobile app in Replit? Diagnose the native build, payments, auth, and App Store gaps before choosing direct publish, repair, or rebuild.
Read article →Learn what a vibe-coded app audit should inspect, what the report must decide, and when to fix, rebuild, or prepare for mobile launch.
Read article →If your Expo app builds locally but EAS production builds fail, diagnose config, dependencies, env vars, credentials, and rebuild risk before launch.
Read article →React Native Supabase auth can look fixed in preview and still trap users in stale sessions. Diagnose storage, redirects, listeners, and RLS before launch.
Read article →If RevenueCat purchases succeed but paid access stays locked, audit entitlement IDs, app user IDs, cache, sandbox, restore, and access gates.
Read article →Before you hire help, verify the build, signing, privacy, paywall, analytics, and review assets a React Native submission service should own.
Read article →A practical triage guide for Expo apps that work locally but crash in TestFlight, with fix versus rebuild decision rules.
Read article →If your Lovable prototype breaks after the demo, diagnose auth, state, backend, mobile, and launch gaps before you keep prompting.
Read article →A practical audit for Cursor-built React Native apps that need stable auth, payments, analytics, TestFlight, and App Store readiness.
Read article →AI tools can generate a convincing React Native demo fast. Here is why those apps often break before App Store launch, and what founders should fix first.
Read article →A practical triage framework for founders stuck with a vibe-coded React Native or Expo app: what to keep, what to fix, and when to rebuild.
Read article →A launch-readiness checklist for founders who built an Expo or React Native app with AI tools and now need authentication, payments, analytics, and App Store submission.
Read article →A practical checklist for founders who used AI tools to build a React Native app and now need to fix bugs, clean architecture, and prepare for launch.
Read article →A code audit checklist for React Native and Expo apps built with AI tools: architecture, dependencies, auth, payments, analytics, App Store readiness, and rebuild risk.
Read article →Cursor can help you build a React Native prototype fast. Here is what still needs to happen before the app can support users, payments, analytics, and App Store launch.
Read article →Lovable can help founders shape a product fast, but App Store launch requires native mobile infrastructure. Here is the path from Lovable prototype to launch-ready app.
Read article →If an AI-generated Bolt or Expo app has broken authentication, payment, or subscription flows, use this order of operations before you keep patching screens.
Read article →A paywall generated by AI may look finished, but RevenueCat, entitlement checks, restore purchases, analytics, and error states make it launch-ready.
Read article →AI coding tools sometimes downgrade Expo or install incompatible packages to clear errors. Here is how to recover the React Native foundation before launch.
Read article →Apple does not reject apps simply because AI helped build them, but AI-generated apps often miss privacy, payments, account deletion, metadata, and review requirements.
Read article →The systematic reason freelancer quotes come in 30 to 60 percent lower than what the project actually costs to ship. Math, examples, and how to stress-test a quote.
Read article →A working framework to estimate mobile app MVP cost based on scope. Plug in your features, get a realistic 2026 budget range across all four delivery paths.
Read article →Every AI app needs one moment that makes users text a friend. Here's the framework for picking yours and why apps with two or more rarely launch.
Read article →Honest decision guide for Expo managed vs bare React Native in 2026. The lines have moved; the right choice has changed.
Read article →When a 1-hour React Native consulting call beats hiring a full agency. The 7 problems where an hour with an expert saves you weeks.
Read article →Honest list of React Native agencies and productized studios worth hiring in 2026, with the kind of project each is best for.
Read article →The ASO keyword research process I run on every launch. 90 minutes, no paid tools required, beats most $500-a-month ASO services.
Read article →Honest comparison of RevenueCat and Stripe for mobile app subscription billing in 2026. The cleanest decision rules and the cases where each one wins.
Read article →Every Apple App Store rejection trigger that actually happens in 2026, plus the fix for each. Save weeks of rejection cycles by checking these before submission.
Read article →The honest sub-$2,000 paths are DIY or guided DIY. Done-for-you mobile development starts above that line once both platforms and store submission are included.
Read article →Practitioner's comparison of OpenAI, Anthropic Claude, and Google Gemini for AI mobile apps. Which model wins on quality, cost, latency, and reliability for each task type.
Read article →Tired of generic 'ChatGPT wrapper' lists? Here are 12 specific AI mobile app patterns that are actually monetizing on the App Store right now.
Read article →Real paywall conversion numbers across utility, AI, wellness, and entertainment apps in 2026. What good looks like and how to fix yours if it doesn't hit.
Read article →Honest comparison of the React Native boilerplates that matter in 2026. Strengths, weaknesses, what's actually included, and which one fits your project.
Read article →The honest playbook for building a profitable ChatGPT wrapper in 2026. Pricing, cost control, retention, and the exact mistakes that kill 90 percent of these apps.
Read article →The math on cheap freelancers always looks great until month four. Real breakdown of why the $4,000 quote becomes a $14,000 project.
Read article →The exact 4-week playbook I use to ship AI-powered mobile apps to the App Store. Week by week, with real decisions, real pitfalls, and the stack that makes it repeatable.
Read article →If your mobile app quote doesn't list these 12 items explicitly, you're going to pay for them as 'change orders' later. Here's the full list.
Read article →An honest, practitioner's comparison of three paths to ship a React Native app in 2026: traditional agency, freelancer, or productized MVP studio. Speed, price, risk, and who owns the code at the end.
Read article →The current my Product Build Sprint scope includes iOS, Android, one focused product loop, both store submissions, code ownership, and a four-week delivery guarantee.
Read article →Honest pricing breakdown for building a mobile app in 2026, from a $0 DIY path to a $50k+ full agency build, with real data from 25 apps I shipped to the App Store.
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How I shipped an iOS AI media product with subscriptions, analytics, rendering infrastructure, and App Store execution before it was acquired.
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A production note on shipping Beehiiv newsletter analytics, subscriber insights, and an iOS widget, then selling the product to a new owner.
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A production note on shipping cold-exposure timers, guided breathwork, streak tracking, HealthKit, and subscriptions in one iOS product.
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Titles and tags from roughly the last two weeks. The busiest lane is also the cheapest.
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