Hey, it's Jenny.
Today I've got a case study of a finance major with zero dev background who built an app with AI and hit $20K/month in just 6 months.
Normally, to get to that kind of revenue, you'd need a dev team or at least a few years of coding experience, right? But this guy coded his entire app in 3 days using just Cursor and ChatGPT.
But the real story isn't about the building.
The app Mau Baron built is called Prayer Lock. It locks your phone, and the only way to unlock it is by praying.
When you open the app, it asks two questions: "How's your relationship with God today?" and "How are you feeling?" Based on your answers, AI generates a personalized prayer. Read it out loud, and your apps unlock.
No database. No sign-up. Everything's stored on-device. As Mau puts it, "Making users sign up is friction. And I save on DB costs too. People worry about losing data when they switch phones? Almost nobody actually thinks about that."
In 6 months: 58,000 downloads, 6,700 reviews, 4.9-star rating. A review rate above 12% puts it in the top tier on the App Store.
Revenue grew fast: October $10K → November $15K → December $21K — that's over 50% month-over-month growth. The paid conversion rate is 43%, and revenue per paying user is $23.6.
Pricing: $49.99/year or $9.99/week.
Mau discovered OpenAI's Codex back in 2022, fell in love with AI, and taught himself to code. In January 2025, he was building an adult content AI app. After finishing it, he felt disgusted with himself. So he made what he calls "the weirdest pivot in history" — into Christian apps.