I Built a $10K/Month App in 88 Days

Saw a breakdown of an app's onboarding (a common post format on X), realized he could make his own angle on it, add a few obvious missing features and make the design premium. Picked health and fitness, a category he expected to make money. The app is 'not really anything special'; premium design and nice UI are the main value proposition.

For every asset in the app, download a batch of images from Pinterest and make them your own with GPT Image (2, now 2.5; free with an OpenAI subscription). Use images heavily, especially during onboarding, because people respond to visuals and it makes the app feel more interactive.

Before building: draw the UI (even a wireframe) in Figma, map a basic entity relationship diagram of the data tables and a basic infrastructure diagram of how data flows between services. Then give all the mockups to ChatGPT (his coding agent, $100/month plan), which builds the whole flow and UI.

Once the app is live, run A/B tests and iterations, primarily on the paywall, and also on prices and pricing options. Uses RevenueCat for monetization tracking and remote paywalls. Minimum: test at least the paywall.

Step one of the Apple Ads playbook: have a strong App Store page, because the screenshots are what searchers see and act as the ad creative. He mocks up the screenshots in Figma and has GPT Image do final touches; alternatively make them with AI or hire a designer for about $50-100.

Start with Apple's $100 free credit; no big budget needed. Create the campaign with Search Match turned off and exact-match keywords only, using the names of your big competitors (e.g. searches for Duolingo show your app as the ad). Start at Apple's recommended max bid and give it at least 2 days. If it still isn't spending after a couple of days, someone is outbidding you, so raise the bid to match.

Set up attribution first: a few lines of code in the app plus a few clicks in RevenueCat (uses AppsFlyer as MMP, free up to 12,000 installs). Once there is spend data, export from RevenueCat and from Apple Ads, combine them, give them to your AI agent and ask it to find the best-performing keywords/ads. Do it once a day as part of the morning routine; he does the same with a daily TikTok ad report.

Scroll TikTok in your niche, find videos that already went viral organically and remake them yourself. He ran five formats, one post each (five ads total), with about $50 of spend per ad. Keep ads running if they convert or are only slightly unprofitable, since early on the ad account needs signal to learn whom to target (lose money on the account, not on the app); stop ads that are very unprofitable. Decide up front how much you are willing to lose to find a winner.

Keep only the ads that do well and raise their budgets gradually, by 20% every few days. Never increase by more than 20% every few days; TikTok itself advises this despite wanting you to spend more.

Turn on goal-based budget increase with a target cost per acquisition ('I want customers at price X'). TikTok then controls spend: instead of manual increases every few days, it raises the budget automatically for as long as the ads hit the target CPA.

Aim for profitability on initial transactions alone. Daily P&L per ad: realized LTV (revenue divided by paying customers) minus CPA, minus Apple's 15% (join the App Store Small Business Program, otherwise you pay 30%), minus RevenueCat's 1%, minus VAT (none when selling to the US, about 20% on EU subscriptions; target the US when starting). Review it each morning with the TikTok ad report.

Went all-in on building the app while sharing the journey on X, including videos and articles such as how he grew the app to $13K/month. The host found him through these posts and credits their authentic, human storytelling.